diff --git a/doc/files.md b/doc/files.md
index 1bc3a1847a..dd966d8ef3 100644
--- a/doc/files.md
+++ b/doc/files.md
@@ -60,6 +60,7 @@ Subdirectory       | File(s)               | Description
 `./`               | `anchors.dat`         | Anchor IP address database, created on shutdown and deleted at startup. Anchors are last known outgoing block-relay-only peers that are tried to re-connect to on startup
 `./`               | `banlist.json`        | Stores the addresses/subnets of banned nodes.
 `./`               | `bitcoin.conf`        | User-defined [configuration settings](bitcoin-conf.md) for `bitcoind` or `bitcoin-qt`. File is not written to by the software and must be created manually. Path can be specified by `-conf` option
+`./`               | `bitcoin_rw.conf`     | Contains [configuration settings](bitcoin-conf.md) modified by `bitcoind` or `bitcoin-qt`; can be specified by `-confrw` option
 `./`               | `bitcoind.pid`        | Stores the process ID (PID) of `bitcoind` or `bitcoin-qt` while running; created at start and deleted on shutdown; can be specified by `-pid` option
 `./`               | `debug.log`           | Contains debug information and general logging generated by `bitcoind` or `bitcoin-qt`; can be specified by `-debuglogfile` option
 `./`               | `fee_estimates.dat`   | Stores statistics used to estimate minimum transaction fees required for confirmation
diff --git a/src/bitcoin-cli.cpp b/src/bitcoin-cli.cpp
index 7683801c93..f270eabba2 100644
--- a/src/bitcoin-cli.cpp
+++ b/src/bitcoin-cli.cpp
@@ -83,6 +83,7 @@ static void SetupCliArgs(ArgsManager& argsman)
 
     argsman.AddArg("-version", "Print version and exit", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
     argsman.AddArg("-conf=<file>", strprintf("Specify configuration file. Relative paths will be prefixed by datadir location. (default: %s)", BITCOIN_CONF_FILENAME), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
+    argsman.AddArg("-confrw=<file>", strprintf("Specify read/write configuration file. Relative paths will be prefixed by the network-specific datadir location. (default: %s)", BITCOIN_RW_CONF_FILENAME), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
     argsman.AddArg("-datadir=<dir>", "Specify data directory", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
     argsman.AddArg("-generate",
                    strprintf("Generate blocks, equivalent to RPC getnewaddress followed by RPC generatetoaddress. Optional positional integer "
@@ -181,13 +182,6 @@ static int AppInitRPC(int argc, char* argv[])
         tfm::format(std::cerr, "Error reading configuration file: %s\n", error);
         return EXIT_FAILURE;
     }
-    // Check for chain settings (BaseParams() calls are only valid after this clause)
-    try {
-        SelectBaseParams(gArgs.GetChainType());
-    } catch (const std::exception& e) {
-        tfm::format(std::cerr, "Error: %s\n", e.what());
-        return EXIT_FAILURE;
-    }
     return CONTINUE_EXECUTION;
 }
 
diff --git a/src/common/args.cpp b/src/common/args.cpp
index 151278a1d7..1cd4090b54 100644
--- a/src/common/args.cpp
+++ b/src/common/args.cpp
@@ -29,15 +29,18 @@
 #include <cstdint>
 #include <cstdlib>
 #include <cstring>
+#include <fstream>
 #include <map>
 #include <optional>
 #include <stdexcept>
 #include <string>
+#include <unordered_set>
 #include <utility>
 #include <variant>
 
 const char * const BITCOIN_CONF_FILENAME = "bitcoin.conf";
 const char * const BITCOIN_SETTINGS_FILENAME = "settings.json";
+const char * const BITCOIN_RW_CONF_FILENAME = "bitcoin_rw.conf";
 
 ArgsManager gArgs;
 
@@ -772,6 +775,12 @@ void ArgsManager::SetConfigFilePath(fs::path path)
     m_config_path = path;
 }
 
+fs::path ArgsManager::GetRWConfigFilePath() const
+{
+    LOCK(cs_args);
+    return *Assert(m_rwconf_path);
+}
+
 ChainType ArgsManager::GetChainType() const
 {
     std::variant<ChainType, std::string> arg = GetChainArg();
@@ -863,9 +872,231 @@ void ArgsManager::LogArgs() const
     for (const auto& setting : m_settings.rw_settings) {
         LogPrintf("Setting file arg: %s = %s\n", setting.first, setting.second.write());
     }
+    logArgsPrefix("R/W config file arg:", "", m_settings.rw_config);
     logArgsPrefix("Command-line arg:", "", m_settings.command_line_options);
 }
 
+namespace {
+
+    // Like std::getline, but includes the EOL character in the result
+    bool getline_with_eol(std::istream& stream, std::string& result)
+    {
+        int current_char;
+        current_char = stream.get();
+        if (current_char == std::char_traits<char>::eof()) {
+            return false;
+        }
+        result.clear();
+        result.push_back(char(current_char));
+        while (current_char != '\n') {
+            current_char = stream.get();
+            if (current_char == std::char_traits<char>::eof()) {
+                break;
+            }
+            result.push_back(char(current_char));
+        }
+        return true;
+    }
+
+    const char * const ModifyRWConfigFile_ws_chars = " \t\r\n";
+
+    void ModifyRWConfigFile_SanityCheck(const std::string& s)
+    {
+        if (s.empty()) {
+            // Dereferencing .begin or .rbegin below is invalid unless the string has at least one character.
+            return;
+        }
+
+        static const char * const newline_chars = "\r\n";
+        static std::string ws_chars(ModifyRWConfigFile_ws_chars);
+        if (s.find_first_of(newline_chars) != std::string::npos) {
+            throw std::invalid_argument("New-line in config name/value");
+        }
+        if (ws_chars.find(*s.begin()) != std::string::npos || ws_chars.find(*s.rbegin()) != std::string::npos) {
+            throw std::invalid_argument("Config name/value has leading/trailing whitespace");
+        }
+    }
+
+    void ModifyRWConfigFile_WriteRemaining(std::ostream& stream_out, const std::map<std::string, std::string>& settings_to_change, std::set<std::string>& setFound)
+    {
+        for (const auto& setting_pair : settings_to_change) {
+            const std::string& key = setting_pair.first;
+            const std::string& val = setting_pair.second;
+            if (setFound.find(key) != setFound.end()) {
+                continue;
+            }
+            setFound.insert(key);
+            ModifyRWConfigFile_SanityCheck(key);
+            ModifyRWConfigFile_SanityCheck(val);
+            stream_out << key << "=" << val << "\n";
+        }
+    }
+} // namespace
+
+void ModifyRWConfigStream(std::istream& stream_in, std::ostream& stream_out, const std::map<std::string, std::string>& settings_to_change)
+{
+    static const char * const ws_chars = ModifyRWConfigFile_ws_chars;
+    std::set<std::string> setFound;
+    std::string s, lineend, linebegin, key;
+    std::string::size_type n, n2;
+    bool inside_group = false, have_eof_nl = true;
+    std::map<std::string, std::string>::const_iterator iterCS;
+    size_t lineno = 0;
+    while (getline_with_eol(stream_in, s)) {
+        ++lineno;
+
+        have_eof_nl = (!s.empty()) && (*s.rbegin() == '\n');
+        n = s.find('#');
+        const bool has_comment = (n != std::string::npos);
+        if (!has_comment) {
+            n = s.size();
+        }
+        if (n > 0) {
+            n2 = s.find_last_not_of(ws_chars, n - 1);
+            if (n2 != std::string::npos) {
+                n = n2 + 1;
+            }
+        }
+        n2 = s.find_first_not_of(ws_chars);
+        if (n2 == std::string::npos || n2 >= n) {
+            // Blank or comment-only line
+            stream_out << s;
+            continue;
+        }
+        lineend = s.substr(n);
+        linebegin = s.substr(0, n2);
+        s = s.substr(n2, n - n2);
+
+        // It is impossible for s to be empty here, due to the blank line check above
+        if (*s.begin() == '[' && *s.rbegin() == ']') {
+            // We don't use sections, so we could possibly just write out the rest of the file - but we need to check for unparsable lines, so we just set a flag to ignore settings from here on
+            ModifyRWConfigFile_WriteRemaining(stream_out, settings_to_change, setFound);
+            inside_group = true;
+            key.clear();
+
+            stream_out << linebegin << s << lineend;
+            continue;
+        }
+
+        n = s.find('=');
+        if (n == std::string::npos) {
+            // Bad line; this causes boost to throw an exception when parsing, so we comment out the entire file
+            stream_in.seekg(0, std::ios_base::beg);
+            stream_out.seekp(0, std::ios_base::beg);
+            if (!(stream_in.good() && stream_out.good())) {
+                throw std::ios_base::failure("Failed to rewind (to comment out existing file)");
+            }
+            // First, write out all the settings we intend to set
+            setFound.clear();
+            ModifyRWConfigFile_WriteRemaining(stream_out, settings_to_change, setFound);
+            // We then define a category to ensure new settings get added before the invalid stuff
+            stream_out << "[INVALID]\n";
+            // Then, describe the problem in a comment
+            stream_out << "# Error parsing line " << lineno << ": " << s << "\n";
+            // Finally, dump the rest of the file commented out
+            while (getline_with_eol(stream_in, s)) {
+                stream_out << "#" << s;
+            }
+            return;
+        }
+
+        if (!inside_group) {
+            // We don't support/use groups, so once we're inside key is always null to avoid setting anything
+            n2 = s.find_last_not_of(ws_chars, n - 1);
+            if (n2 == std::string::npos) {
+                n2 = n - 1;
+            } else {
+                ++n2;
+            }
+            key = s.substr(0, n2);
+        }
+        if ((!key.empty()) && (iterCS = settings_to_change.find(key)) != settings_to_change.end() && setFound.find(key) == setFound.end()) {
+            // This is the key we want to change
+            const std::string& val = iterCS->second;
+            setFound.insert(key);
+            ModifyRWConfigFile_SanityCheck(val);
+            if (has_comment) {
+                // Rather than change a commented line, comment it out entirely (the existing comment may relate to the value) and replace it
+                stream_out << key << "=" << val << "\n";
+                linebegin.insert(linebegin.begin(), '#');
+            } else {
+                // Just modify the value in-line otherwise
+                n2 = s.find_first_not_of(ws_chars, n + 1);
+                if (n2 == std::string::npos) {
+                    n2 = n + 1;
+                }
+                s = s.substr(0, n2) + val;
+            }
+        }
+        stream_out << linebegin << s << lineend;
+    }
+    if (setFound.size() < settings_to_change.size()) {
+        if (!have_eof_nl) {
+            stream_out << "\n";
+        }
+        ModifyRWConfigFile_WriteRemaining(stream_out, settings_to_change, setFound);
+    }
+}
+
+void ArgsManager::ModifyRWConfigFile(const std::map<std::string, std::string>& settings_to_change)
+{
+    LOCK(cs_args);
+    fs::path rwconf_path{GetRWConfigFilePath()};
+    fs::path rwconf_new_path{rwconf_path};
+    rwconf_new_path += ".new";
+    try {
+        fs::remove(rwconf_new_path);
+        std::ofstream streamRWConfigOut(rwconf_new_path, std::ios_base::out | std::ios_base::trunc);
+        if (fs::exists(rwconf_path)) {
+            std::ifstream streamRWConfig(rwconf_path);
+            ::ModifyRWConfigStream(streamRWConfig, streamRWConfigOut, settings_to_change);
+        } else {
+            std::istringstream streamIn;
+            ::ModifyRWConfigStream(streamIn, streamRWConfigOut, settings_to_change);
+        }
+    } catch (...) {
+        fs::remove(rwconf_new_path);
+        throw;
+    }
+    if (!RenameOver(rwconf_new_path, rwconf_path)) {
+        fs::remove(rwconf_new_path);
+        throw std::ios_base::failure(strprintf("Failed to replace %s", fs::PathToString(rwconf_new_path)));
+    }
+    for (const auto& setting_change : settings_to_change) {
+        m_settings.rw_config[setting_change.first] = {setting_change.second};
+    }
+    if (!IsArgNegated("-settings")) {
+        // Also save to settings.json for Core (0.21+) compatibility
+        for (const auto& setting_change : settings_to_change) {
+            m_settings.rw_settings[setting_change.first] = setting_change.second;
+        }
+        WriteSettingsFile();
+    }
+}
+
+void ArgsManager::ModifyRWConfigFile(const std::string& setting_to_change, const std::string& new_value)
+{
+    std::map<std::string, std::string> settings_to_change;
+    settings_to_change[setting_to_change] = new_value;
+    ModifyRWConfigFile(settings_to_change);
+}
+
+void ArgsManager::EraseRWConfigFile()
+{
+    LOCK(cs_args);
+    fs::path rwconf_path{GetRWConfigFilePath()};
+    if (!fs::exists(rwconf_path)) {
+        return;
+    }
+    fs::path rwconf_reset_path = rwconf_path;
+    rwconf_reset_path += ".reset";
+    if (!RenameOver(rwconf_path, rwconf_reset_path)) {
+        if (fs::remove(rwconf_path)) {
+            throw std::ios_base::failure(strprintf("Failed to remove %s", fs::PathToString(rwconf_path)));
+        }
+    }
+}
+
 namespace common {
 #ifdef WIN32
 WinCmdLineArgs::WinCmdLineArgs()
diff --git a/src/common/args.h b/src/common/args.h
index c782d4245c..fda7be39ad 100644
--- a/src/common/args.h
+++ b/src/common/args.h
@@ -25,6 +25,7 @@ class ArgsManager;
 
 extern const char * const BITCOIN_CONF_FILENAME;
 extern const char * const BITCOIN_SETTINGS_FILENAME;
+extern const char * const BITCOIN_RW_CONF_FILENAME;
 
 // Return true if -datadir option points to a valid directory or is not specified.
 bool CheckDataDirOption(const ArgsManager& args);
@@ -94,6 +95,8 @@ std::optional<int64_t> SettingToInt(const common::SettingsValue&);
 bool SettingToBool(const common::SettingsValue&, bool);
 std::optional<bool> SettingToBool(const common::SettingsValue&);
 
+void ModifyRWConfigStream(std::istream& stream_in, std::ostream& stream_out, const std::map<std::string, std::string>& settings_to_change);
+
 class ArgsManager
 {
 public:
@@ -139,11 +142,12 @@ protected:
     bool m_accept_any_command GUARDED_BY(cs_args){true};
     std::list<SectionInfo> m_config_sections GUARDED_BY(cs_args);
     std::optional<fs::path> m_config_path GUARDED_BY(cs_args);
+    std::optional<fs::path> m_rwconf_path GUARDED_BY(cs_args);
     mutable fs::path m_cached_blocks_path GUARDED_BY(cs_args);
     mutable fs::path m_cached_datadir_path GUARDED_BY(cs_args);
     mutable fs::path m_cached_network_datadir_path GUARDED_BY(cs_args);
 
-    [[nodiscard]] bool ReadConfigStream(std::istream& stream, const std::string& filepath, std::string& error, bool ignore_invalid_keys = false);
+    [[nodiscard]] bool ReadConfigStream(std::istream& stream, const std::string& filepath, std::string& error, bool ignore_invalid_keys = false, std::map<std::string, std::vector<common::SettingsValue>>* settings_target = nullptr);
 
     /**
      * Returns true if settings values from the default section should be used,
@@ -182,8 +186,13 @@ protected:
      */
     fs::path GetConfigFilePath() const;
     void SetConfigFilePath(fs::path);
+    fs::path GetRWConfigFilePath() const;
     [[nodiscard]] bool ReadConfigFiles(std::string& error, bool ignore_invalid_keys = false);
 
+    void ModifyRWConfigFile(const std::map<std::string, std::string>& settings_to_change);
+    void ModifyRWConfigFile(const std::string& setting_to_change, const std::string& new_value);
+    void EraseRWConfigFile();
+
     /**
      * Log warnings for options in m_section_only_args when
      * they are specified in the default section but not overridden
diff --git a/src/common/config.cpp b/src/common/config.cpp
index fac4aa314c..42b2eee71f 100644
--- a/src/common/config.cpp
+++ b/src/common/config.cpp
@@ -4,6 +4,7 @@
 
 #include <common/args.h>
 
+#include <chainparamsbase.h>
 #include <common/settings.h>
 #include <logging.h>
 #include <sync.h>
@@ -90,7 +91,7 @@ bool IsConfSupported(KeyInfo& key, std::string& error) {
     return true;
 }
 
-bool ArgsManager::ReadConfigStream(std::istream& stream, const std::string& filepath, std::string& error, bool ignore_invalid_keys)
+bool ArgsManager::ReadConfigStream(std::istream& stream, const std::string& filepath, std::string& error, bool ignore_invalid_keys, std::map<std::string, std::vector<common::SettingsValue>>* settings_target)
 {
     LOCK(cs_args);
     std::vector<std::pair<std::string, std::string>> options;
@@ -106,6 +107,9 @@ bool ArgsManager::ReadConfigStream(std::istream& stream, const std::string& file
             if (!value) {
                 return false;
             }
+            if (settings_target) {
+                (*settings_target)[key.name].push_back(*value);
+            } else
             m_settings.ro_config[key.section][key.name].push_back(*value);
         } else {
             if (ignore_invalid_keys) {
@@ -124,6 +128,7 @@ bool ArgsManager::ReadConfigFiles(std::string& error, bool ignore_invalid_keys)
     {
         LOCK(cs_args);
         m_settings.ro_config.clear();
+        m_settings.rw_config.clear();
         m_config_sections.clear();
         m_config_path = AbsPathForConfigVal(*this, GetPathArg("-conf", BITCOIN_CONF_FILENAME), /*net_specific=*/false);
     }
@@ -214,12 +219,31 @@ bool ArgsManager::ReadConfigFiles(std::string& error, bool ignore_invalid_keys)
         }
     }
 
+    // Check for chain settings (BaseParams() calls are only valid after this clause)
+    try {
+        SelectBaseParams(gArgs.GetChainType());
+    } catch (const std::exception& e) {
+        error = e.what();
+        return false;
+    }
+
     // If datadir is changed in .conf file:
     ClearPathCache();
     if (!CheckDataDirOption(*this)) {
         error = strprintf("specified data directory \"%s\" does not exist.", GetArg("-datadir", ""));
         return false;
     }
+
+    LOCK(cs_args);
+    m_rwconf_path = AbsPathForConfigVal(*this, GetPathArg("-confrw", BITCOIN_RW_CONF_FILENAME));
+    const auto rwconf_path{GetRWConfigFilePath()};
+    std::ifstream rwconf_stream(rwconf_path);
+    if (rwconf_stream.good()) {
+        if (!ReadConfigStream(rwconf_stream, fs::PathToString(rwconf_path), error, ignore_invalid_keys, &m_settings.rw_config)) {
+            return false;
+        }
+    }
+
     return true;
 }
 
diff --git a/src/common/settings.cpp b/src/common/settings.cpp
index c1520dacd2..576ef285ac 100644
--- a/src/common/settings.cpp
+++ b/src/common/settings.cpp
@@ -24,6 +24,7 @@ namespace {
 enum class Source {
    FORCED,
    COMMAND_LINE,
+   CONFIG_FILE_RW,
    RW_SETTINGS,
    CONFIG_FILE_NETWORK_SECTION,
    CONFIG_FILE_DEFAULT_SECTION
@@ -48,6 +49,10 @@ static void MergeSettings(const Settings& settings, const std::string& section,
     if (auto* values = FindKey(settings.command_line_options, name)) {
         fn(SettingsSpan(*values), Source::COMMAND_LINE);
     }
+    // Merge in the rw config file
+    if (auto* values = FindKey(settings.rw_config, name)) {
+        fn(SettingsSpan(*values), Source::CONFIG_FILE_RW);
+    }
     // Merge in the read-write settings
     if (const SettingsValue* value = FindKey(settings.rw_settings, name)) {
         fn(SettingsSpan(*value), Source::RW_SETTINGS);
@@ -165,7 +170,7 @@ SettingsValue GetSetting(const Settings& settings,
         // the config file the precedence is reversed for all settings except
         // chain type settings.
         const bool reverse_precedence =
-            (source == Source::CONFIG_FILE_NETWORK_SECTION || source == Source::CONFIG_FILE_DEFAULT_SECTION) &&
+            (source == Source::CONFIG_FILE_RW || source == Source::CONFIG_FILE_NETWORK_SECTION || source == Source::CONFIG_FILE_DEFAULT_SECTION) &&
             !get_chain_type;
 
         // Weird behavior preserved for backwards compatibility: Negated
@@ -217,7 +222,7 @@ std::vector<SettingsValue> GetSettingsList(const Settings& settings,
         // settings will be brought back from the dead (but earlier command
         // line settings will still be ignored).
         const bool add_zombie_config_values =
-            (source == Source::CONFIG_FILE_NETWORK_SECTION || source == Source::CONFIG_FILE_DEFAULT_SECTION) &&
+            (source == Source::CONFIG_FILE_RW || source == Source::CONFIG_FILE_NETWORK_SECTION || source == Source::CONFIG_FILE_DEFAULT_SECTION) &&
             !prev_negated_empty;
 
         // Ignore settings in default config section if requested.
diff --git a/src/common/settings.h b/src/common/settings.h
index 0e9d376e23..e00f580314 100644
--- a/src/common/settings.h
+++ b/src/common/settings.h
@@ -34,6 +34,8 @@ struct Settings {
     std::map<std::string, SettingsValue> forced_settings;
     //! Map of setting name to list of command line values.
     std::map<std::string, std::vector<SettingsValue>> command_line_options;
+    //! Map of setting name to list of r/w config file values.
+    std::map<std::string, std::vector<SettingsValue>> rw_config;
     //! Map of setting name to read-write file setting value.
     std::map<std::string, SettingsValue> rw_settings;
     //! Map of config section name and setting name to list of config file values.
diff --git a/src/init.cpp b/src/init.cpp
index d95a166117..bf92f2a1e8 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -493,6 +493,7 @@ void SetupServerArgs(ArgsManager& argsman)
     argsman.AddArg("-blocksonly", strprintf("Whether to reject transactions from network peers. Disables automatic broadcast and rebroadcast of transactions, unless the source peer has the 'forcerelay' permission. RPC transactions are not affected. (default: %u)", DEFAULT_BLOCKSONLY), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
     argsman.AddArg("-coinstatsindex", strprintf("Maintain coinstats index used by the gettxoutsetinfo RPC (default: %u)", DEFAULT_COINSTATSINDEX), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
     argsman.AddArg("-conf=<file>", strprintf("Specify path to read-only configuration file. Relative paths will be prefixed by datadir location (only useable from command line, not configuration file) (default: %s)", BITCOIN_CONF_FILENAME), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
+    argsman.AddArg("-confrw=<file>", strprintf("Specify read/write configuration file. Relative paths will be prefixed by the network-specific datadir location (default: %s)", BITCOIN_RW_CONF_FILENAME), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
     argsman.AddArg("-datadir=<dir>", "Specify data directory", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
     argsman.AddArg("-dbbatchsize", strprintf("Maximum database write batch size in bytes (default: %u)", nDefaultDbBatchSize), ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::OPTIONS);
     argsman.AddArg("-dbcache=<n>", strprintf("Maximum database cache size <n> MiB (%d to %d, default: %d). In addition, unused mempool memory is shared for this cache (see -maxmempool).", nMinDbCache, nMaxDbCache, nDefaultDbCache), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
diff --git a/src/init/common.cpp b/src/init/common.cpp
index 1d246241c1..fefb29c9ac 100644
--- a/src/init/common.cpp
+++ b/src/init/common.cpp
@@ -136,6 +136,15 @@ bool StartLogging(const ArgsManager& args)
         LogPrintf("Config file: %s (not found, skipping)\n", fs::PathToString(config_file_path));
     }
 
+    fs::path rwconfig_file_path = args.GetRWConfigFilePath();
+    if (fs::exists(rwconfig_file_path)) {
+        LogPrintf("R/W Config file: %s\n", fs::PathToString(rwconfig_file_path));
+    } else if (gArgs.IsArgSet("-confrw")) {
+        InitWarning(strprintf(_("The specified R/W config file %s does not exist"), fs::PathToString(rwconfig_file_path)));
+    } else {
+        LogPrintf("R/W Config file: %s (not found, skipping)\n", fs::PathToString(rwconfig_file_path));
+    }
+
     // Log the config arguments to debug.log
     args.LogArgs();
 
diff --git a/src/qt/optionsmodel.cpp b/src/qt/optionsmodel.cpp
index 774210455f..0d2c7576c3 100644
--- a/src/qt/optionsmodel.cpp
+++ b/src/qt/optionsmodel.cpp
@@ -312,6 +312,9 @@ void OptionsModel::Reset()
     QString dataDir = GUIUtil::getDefaultDataDirectory();
     dataDir = settings.value("strDataDir", dataDir).toString();
 
+    // Remove rw config file
+    gArgs.EraseRWConfigFile();
+
     // Remove all entries from our QSettings object
     settings.clear();
 
diff --git a/src/qt/test/apptests.cpp b/src/qt/test/apptests.cpp
index 10abcb00eb..d176ea5ae9 100644
--- a/src/qt/test/apptests.cpp
+++ b/src/qt/test/apptests.cpp
@@ -5,6 +5,7 @@
 #include <qt/test/apptests.h>
 
 #include <chainparams.h>
+#include <common/args.h>
 #include <key.h>
 #include <logging.h>
 #include <qt/bitcoin.h>
@@ -66,6 +67,14 @@ void AppTests::appTests()
     }
 #endif
 
+    {
+        // Need to ensure datadir is setup so resetting settings can delete the non-existent bitcoin_rw.conf
+        std::string error;
+        if (!gArgs.ReadConfigFiles(error, true)) {
+            QWARN("Error in readConfigFiles");
+        }
+    }
+
     qRegisterMetaType<interfaces::BlockAndHeaderTipInfo>("interfaces::BlockAndHeaderTipInfo");
     m_app.parameterSetup();
     QVERIFY(m_app.createOptionsModel(/*resetSettings=*/true));
diff --git a/src/test/util_tests.cpp b/src/test/util_tests.cpp
index 3d5d29f0e5..7369c77f7b 100644
--- a/src/test/util_tests.cpp
+++ b/src/test/util_tests.cpp
@@ -2037,4 +2037,157 @@ BOOST_AUTO_TEST_CASE(clearshrink_test)
     }
 }
 
+static std::string CheckModifyRWConfigFile(std::map<std::string, std::string>& settings_to_change, const std::string& current_config_file)
+{
+    std::istringstream stream_in(current_config_file);
+    std::ostringstream stream_out;
+    try {
+        ModifyRWConfigStream(stream_in, stream_out, settings_to_change);
+    } catch (...) {
+        settings_to_change.clear();
+        throw;
+    }
+    settings_to_change.clear();
+    return stream_out.str();
+}
+
+BOOST_AUTO_TEST_CASE(test_ModifyRWConfigFile)
+{
+    std::map<std::string, std::string> cs;
+
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b"), "a=b");
+
+    cs["a"] = "c";
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b"), "a=c");
+    BOOST_CHECK(cs.empty());
+
+    // Multi-char name/value
+    cs["ab"] = "cd";
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "ab=bc"), "ab=cd");
+
+    // Preserved final newline
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b\n"), "a=b\n");
+    cs["a"] = "c";
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b\n"), "a=c\n");
+
+    // Preserved final tab
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b\t"), "a=b\t");
+    cs["a"] = "c";
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b\t"), "a=c\t");
+
+    // Preserved final space
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b "), "a=b ");
+    cs["a"] = "c";
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b "), "a=c ");
+
+    // Preserved final crnl
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b\r\n"), "a=b\r\n");
+    cs["a"] = "c";
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b\r\n"), "a=c\r\n");
+
+    // Empty file
+    cs["a"] = "c";
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, ""), "a=c\n");
+
+    // Ignore k=v in comment
+    cs["a"] = "c";
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "#a=b"), "#a=b\na=c\n");
+
+    // Preserved comment
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b\t# c"), "a=b\t# c");
+
+    // Commented out commented value
+    cs["a"] = "c";
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b\t# c"), "a=c\n#a=b\t# c");
+
+    // Preserved whitespace before name
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, " \t \ta=b"), " \t \ta=b");
+    cs["a"] = "c";
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, " \t \ta=b"), " \t \ta=c");
+
+    // Preserved whitespace after name
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a \t \t=b"), "a \t \t=b");
+    cs["a"] = "c";
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a \t \t=b"), "a \t \t=c");
+
+    // Preserved whitespace before value
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a= \t \tb"), "a= \t \tb");
+    cs["a"] = "c";
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a= \t \tb"), "a= \t \tc");
+
+    // Modifying value between others
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b\nab=bc\nd=e"), "a=b\nab=bc\nd=e");
+    cs["ab"] = "x";
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b\nab=bc\nd=e"), "a=b\nab=x\nd=e");
+
+    // Blank key/value
+    cs["ab"] = "";
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b\nab=bc\nd=e"), "a=b\nab=\nd=e");
+    cs[""] = "x";
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b\nab=bc\nd=e"), "a=b\nab=bc\nd=e\n=x\n");
+
+    // Blank line in source
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b\n\nab=bc\n\nd=e"), "a=b\n\nab=bc\n\nd=e");
+    cs["ab"] = "x";
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b\n\nab=bc\n\nd=e"), "a=b\n\nab=x\n\nd=e");
+
+    // Duplicate keys in the source
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b\nab=bc\nf=x\nab=zx\nd=e"), "a=b\nab=bc\nf=x\nab=zx\nd=e");
+    cs["ab"] = "x";
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b\nab=bc\nf=x\nab=zx\nd=e"), "a=b\nab=x\nf=x\nab=zx\nd=e");
+
+    // Comment out entire file if invalid input line
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b\nab=bc\nGARBAGE\nd=e"), "[INVALID]\n# Error parsing line 3: GARBAGE\n#a=b\n#ab=bc\n#GARBAGE\n#d=e");
+    cs["ab"] = "x";
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b\nab=bc\nGARBAGE\nd=e"), "ab=x\n[INVALID]\n# Error parsing line 3: GARBAGE\n#a=b\n#ab=bc\n#GARBAGE\n#d=e");
+    cs["ab"] = "x";
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b\nab=bc\nGARBAGE\nd=e\n"), "ab=x\n[INVALID]\n# Error parsing line 3: GARBAGE\n#a=b\n#ab=bc\n#GARBAGE\n#d=e\n");
+
+    // Whitespace inside values
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b\nab=b\t \t c\nd=e"), "a=b\nab=b\t \t c\nd=e");
+    cs["ab"] = "x \t \tx";
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b\nab=b\t \t c\nd=e"), "a=b\nab=x \t \tx\nd=e");
+
+    // Newline inside name/value
+    cs["a"] = "x\nx";
+    BOOST_REQUIRE_THROW(CheckModifyRWConfigFile(cs, ""), std::invalid_argument);
+    cs["a"] = "x\rx";
+    BOOST_REQUIRE_THROW(CheckModifyRWConfigFile(cs, ""), std::invalid_argument);
+    cs["a\nb"] = "x";
+    BOOST_REQUIRE_THROW(CheckModifyRWConfigFile(cs, ""), std::invalid_argument);
+    cs["a\rb"] = "x";
+    BOOST_REQUIRE_THROW(CheckModifyRWConfigFile(cs, ""), std::invalid_argument);
+
+    // Whitespace leading/trailing name/value
+    cs["a"] = " x";
+    BOOST_REQUIRE_THROW(CheckModifyRWConfigFile(cs, ""), std::invalid_argument);
+    cs["a"] = "\tx";
+    BOOST_REQUIRE_THROW(CheckModifyRWConfigFile(cs, ""), std::invalid_argument);
+    cs[" a"] = "x";
+    BOOST_REQUIRE_THROW(CheckModifyRWConfigFile(cs, ""), std::invalid_argument);
+    cs["\ta"] = "x";
+    BOOST_REQUIRE_THROW(CheckModifyRWConfigFile(cs, ""), std::invalid_argument);
+    cs["a"] = "x ";
+    BOOST_REQUIRE_THROW(CheckModifyRWConfigFile(cs, ""), std::invalid_argument);
+    cs["a"] = "x\t";
+    BOOST_REQUIRE_THROW(CheckModifyRWConfigFile(cs, ""), std::invalid_argument);
+    cs["a "] = "x";
+    BOOST_REQUIRE_THROW(CheckModifyRWConfigFile(cs, ""), std::invalid_argument);
+    cs["a\t"] = "x";
+    BOOST_REQUIRE_THROW(CheckModifyRWConfigFile(cs, ""), std::invalid_argument);
+
+    // Ignore groups
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b\n[group]\nab=bc\nd=e"), "a=b\n[group]\nab=bc\nd=e");
+    cs["ab"] = "x";
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b\n[group]\nab=bc\nd=e"), "a=b\nab=x\n[group]\nab=bc\nd=e");
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b\n\t [group] \t#c\nab=bc\nd=e"), "a=b\n\t [group] \t#c\nab=bc\nd=e");
+    cs["ab"] = "x";
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b\n\t [group] \t#c\nab=bc\nd=e"), "a=b\nab=x\n\t [group] \t#c\nab=bc\nd=e");
+
+    // Comment out entire file if invalid input line, even after a group
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b\n[group]\nab=bc\nGARBAGE\nd=e"), "[INVALID]\n# Error parsing line 4: GARBAGE\n#a=b\n#[group]\n#ab=bc\n#GARBAGE\n#d=e");
+    cs["ab"] = "x";
+    BOOST_CHECK_EQUAL(CheckModifyRWConfigFile(cs, "a=b\n[group]\nab=bc\nGARBAGE\nd=e"), "ab=x\n[INVALID]\n# Error parsing line 4: GARBAGE\n#a=b\n#[group]\n#ab=bc\n#GARBAGE\n#d=e");
+}
+
 BOOST_AUTO_TEST_SUITE_END()