diff --git a/share/qt/Info.plist.in b/share/qt/Info.plist.in
--- a/share/qt/Info.plist.in
+++ b/share/qt/Info.plist.in
@@ -38,7 +38,7 @@
   <true/>
 
   <key>CFBundleIdentifier</key>
-  <string>org.bitcoincash.BitcoinABC-Qt</string>
+  <string>org.bitcoinabc.BitcoinABC-Qt</string>
 
   <key>CFBundleURLTypes</key>
   <array>
diff --git a/src/qt/bitcoin.cpp b/src/qt/bitcoin.cpp
--- a/src/qt/bitcoin.cpp
+++ b/src/qt/bitcoin.cpp
@@ -49,6 +49,7 @@
 #include <QMessageBox>
 #include <QSettings>
 #include <QSslConfiguration>
+#include <QStringList>
 #include <QThread>
 #include <QTimer>
 #include <QTranslator>
@@ -540,6 +541,44 @@
 }
 
 #ifndef BITCOIN_QT_TEST
+
+static void MigrateSettings() {
+    assert(!QApplication::applicationName().isEmpty());
+
+    static const QString legacyAppName("Bitcoin-Qt"),
+#ifdef Q_OS_DARWIN
+        // Macs and/or iOS et al use a domain-style name for Settings
+        // files. All other platforms use a simple orgname. This
+        // difference is documented in the QSettings class documentation.
+        legacyOrg("bitcoin.org");
+#else
+        legacyOrg("Bitcoin");
+#endif
+    QSettings
+        // below picks up settings file location based on orgname,appname
+        legacy(legacyOrg, legacyAppName),
+        // default c'tor below picks up settings file location based on
+        // QApplication::applicationName(), et al -- which was already set
+        // in main()
+        abc;
+#ifdef Q_OS_DARWIN
+    // Disable bogus OSX keys from MacOS system-wide prefs that may cloud our
+    // judgement ;) (this behavior is also documented in QSettings docs)
+    legacy.setFallbacksEnabled(false);
+    abc.setFallbacksEnabled(false);
+#endif
+    const QStringList legacyKeys(legacy.allKeys());
+
+    // We only migrate settings if we have Core settings but no Bitcoin-ABC
+    // settings
+    if (!legacyKeys.isEmpty() && abc.allKeys().isEmpty()) {
+        for (const QString &key : legacyKeys) {
+            // now, copy settings over
+            abc.setValue(key, legacy.value(key));
+        }
+    }
+}
+
 int main(int argc, char *argv[]) {
     SetupEnvironment();
 
@@ -597,9 +636,17 @@
     /// 3. Application identification
     // must be set before OptionsModel is initialized or translations are
     // loaded, as it is used to locate QSettings.
+    // Note: If you move these calls somewhere else, be sure to bring
+    // MigrateSettings() below along for the ride.
     QApplication::setOrganizationName(QAPP_ORG_NAME);
     QApplication::setOrganizationDomain(QAPP_ORG_DOMAIN);
     QApplication::setApplicationName(QAPP_APP_NAME_DEFAULT);
+    // Migrate settings from core's/our old GUI settings to Bitcoin ABC
+    // only if core's exist but Bitcoin ABC's doesn't.
+    // NOTE -- this function needs to be called *after* the above 3 lines
+    // that set the app orgname and app name! If you move the above 3 lines
+    // to elsewhere, take this call with you!
+    MigrateSettings();
     GUIUtil::SubstituteFonts(GetLangTerritory());
 
     /// 4. Initialization of translations, so that intro dialog is in user's
diff --git a/src/qt/guiconstants.h b/src/qt/guiconstants.h
--- a/src/qt/guiconstants.h
+++ b/src/qt/guiconstants.h
@@ -48,9 +48,9 @@
 /* Number of frames in spinner animation */
 #define SPINNER_FRAMES 36
 
-#define QAPP_ORG_NAME "Bitcoin"
-#define QAPP_ORG_DOMAIN "bitcoin.org"
-#define QAPP_APP_NAME_DEFAULT "Bitcoin-Qt"
-#define QAPP_APP_NAME_TESTNET "Bitcoin-Qt-testnet"
+#define QAPP_ORG_NAME "BitcoinABC"
+#define QAPP_ORG_DOMAIN "bitcoinabc.org"
+#define QAPP_APP_NAME_DEFAULT "BitcoinABC-Qt"
+#define QAPP_APP_NAME_TESTNET "BitcoinABC-Qt-testnet"
 
 #endif // BITCOIN_QT_GUICONSTANTS_H
diff --git a/src/qt/macnotificationhandler.mm b/src/qt/macnotificationhandler.mm
--- a/src/qt/macnotificationhandler.mm
+++ b/src/qt/macnotificationhandler.mm
@@ -13,7 +13,7 @@
 - (NSString *)__bundleIdentifier
 {
     if (self == [NSBundle mainBundle]) {
-        return @"org.bitcoincash.BitcoinABC-Qt";
+        return @"org.bitcoinabc.BitcoinABC-Qt";
     } else {
         return [self __bundleIdentifier];
     }
diff --git a/src/qt/test/test_main.cpp b/src/qt/test/test_main.cpp
--- a/src/qt/test/test_main.cpp
+++ b/src/qt/test/test_main.cpp
@@ -46,7 +46,7 @@
     // Don't remove this, it's needed to access
     // QCoreApplication:: in the tests
     QCoreApplication app(argc, argv);
-    app.setApplicationName("Bitcoin-Qt-test");
+    app.setApplicationName("BitcoinABC-Qt-test");
 
     SSL_library_init();