diff --git a/app/src/main/java/it/niedermann/owncloud/notes/android/DarkModeSetting.java b/app/src/main/java/it/niedermann/owncloud/notes/android/DarkModeSetting.java
new file mode 100644
index 00000000..e9d6a0a0
--- /dev/null
+++ b/app/src/main/java/it/niedermann/owncloud/notes/android/DarkModeSetting.java
@@ -0,0 +1,64 @@
+package it.niedermann.owncloud.notes.android;
+
+import androidx.appcompat.app.AppCompatDelegate;
+
+import java.util.NoSuchElementException;
+
+/**
+ * Possible values of the Dark Mode Setting.
+ * <p>
+ * The Dark Mode Setting can be stored in {@link android.content.SharedPreferences} as String by using {@link DarkModeSetting#name()} and received via {@link DarkModeSetting#valueOf(String)}.
+ * <p>
+ * Additionally, the equivalent {@link AppCompatDelegate}-Mode can be received via {@link #getModeId()}. To convert a {@link AppCompatDelegate}-Mode to a {@link DarkModeSetting}, use {@link #fromModeID(int)}
+ *
+ * @see AppCompatDelegate#MODE_NIGHT_YES
+ * @see AppCompatDelegate#MODE_NIGHT_NO
+ * @see AppCompatDelegate#MODE_NIGHT_FOLLOW_SYSTEM
+ */
+public enum DarkModeSetting {
+    /**
+     * Always use light mode.
+     */
+    LIGHT(AppCompatDelegate.MODE_NIGHT_NO),
+    /**
+     * Always use dark mode.
+     */
+    DARK(AppCompatDelegate.MODE_NIGHT_YES),
+    /**
+     * Follow the global system setting for dark mode.
+     */
+    SYSTEM_DEFAULT(AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM);
+
+    private final int modeId;
+
+    DarkModeSetting(int modeId) {
+        this.modeId = modeId;
+    }
+
+    public int getModeId() {
+        return modeId;
+    }
+
+    /**
+     * Returns the instance of {@link DarkModeSetting} that corresponds to the ModeID of {@link AppCompatDelegate}
+     * <p>
+     * Possible ModeIDs are:
+     * <ul>
+     *     <li>{@link AppCompatDelegate#MODE_NIGHT_YES}</li>
+     *     <li>{@link AppCompatDelegate#MODE_NIGHT_NO}</li>
+     *     <li>{@link AppCompatDelegate#MODE_NIGHT_FOLLOW_SYSTEM}</li>
+     * </ul>
+     *
+     * @param id One of the {@link AppCompatDelegate}-Night-Modes
+     * @return An instance of {@link DarkModeSetting}
+     */
+    public static DarkModeSetting fromModeID(int id) {
+        for (DarkModeSetting value : DarkModeSetting.values()) {
+            if (value.modeId == id) {
+                return value;
+            }
+        }
+
+        throw new NoSuchElementException("No NightMode with ID " + id + " found");
+    }
+}
diff --git a/app/src/main/java/it/niedermann/owncloud/notes/android/activity/SelectSingleNoteActivity.java b/app/src/main/java/it/niedermann/owncloud/notes/android/activity/SelectSingleNoteActivity.java
index 0d60bef7..d08a830e 100644
--- a/app/src/main/java/it/niedermann/owncloud/notes/android/activity/SelectSingleNoteActivity.java
+++ b/app/src/main/java/it/niedermann/owncloud/notes/android/activity/SelectSingleNoteActivity.java
@@ -59,7 +59,7 @@ public class SelectSingleNoteActivity extends NotesListViewActivity {
 
         sp.putLong(SingleNoteWidget.WIDGET_KEY + appWidgetId, noteID);
         sp.putLong(SingleNoteWidget.ACCOUNT_ID_KEY + appWidgetId, note.getAccountId());
-        sp.putBoolean(SingleNoteWidget.DARK_THEME_KEY + appWidgetId, Notes.getAppTheme(getApplicationContext()));
+        sp.putString(SingleNoteWidget.DARK_THEME_KEY + appWidgetId, Notes.getAppTheme(getApplicationContext()).name());
         sp.apply();
 
         Intent updateIntent = new Intent(AppWidgetManager.ACTION_APPWIDGET_UPDATE, null,
diff --git a/app/src/main/java/it/niedermann/owncloud/notes/android/appwidget/NoteListWidget.java b/app/src/main/java/it/niedermann/owncloud/notes/android/appwidget/NoteListWidget.java
index a9a477cc..1922a625 100644
--- a/app/src/main/java/it/niedermann/owncloud/notes/android/appwidget/NoteListWidget.java
+++ b/app/src/main/java/it/niedermann/owncloud/notes/android/appwidget/NoteListWidget.java
@@ -13,8 +13,10 @@ import android.util.Log;
 import android.widget.RemoteViews;
 
 import it.niedermann.owncloud.notes.R;
+import it.niedermann.owncloud.notes.android.DarkModeSetting;
 import it.niedermann.owncloud.notes.android.activity.EditNoteActivity;
 import it.niedermann.owncloud.notes.android.activity.NotesListViewActivity;
+import it.niedermann.owncloud.notes.util.Notes;
 
 public class NoteListWidget extends AppWidgetProvider {
     private static final String TAG = NoteListWidget.class.getSimpleName();
@@ -28,7 +30,7 @@ public class NoteListWidget extends AppWidgetProvider {
 
     static void updateAppWidget(Context context, AppWidgetManager awm, int[] appWidgetIds) {
         RemoteViews views;
-        boolean darkTheme;
+        String darkTheme;
 
         for (int appWidgetId : appWidgetIds) {
             SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(context);
@@ -40,7 +42,7 @@ public class NoteListWidget extends AppWidgetProvider {
             }
 
             String category = sp.getString(NoteListWidget.WIDGET_CATEGORY_KEY + appWidgetId, null);
-            darkTheme = sp.getBoolean(NoteListWidget.DARK_THEME_KEY + appWidgetId, false);
+            darkTheme = sp.getString(NoteListWidget.DARK_THEME_KEY + appWidgetId, DarkModeSetting.SYSTEM_DEFAULT.name());
 
             Intent serviceIntent = new Intent(context, NoteListWidgetService.class);
             serviceIntent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetId);
@@ -70,7 +72,7 @@ public class NoteListWidget extends AppWidgetProvider {
                     (new Intent(context, EditNoteActivity.class)),
                     PendingIntent.FLAG_UPDATE_CURRENT);
 
-            if (darkTheme) {
+            if (Notes.isDarkThemeActive(context, DarkModeSetting.valueOf(darkTheme))) {
                 views = new RemoteViews(context.getPackageName(), R.layout.widget_note_list_dark);
                 views.setTextViewText(R.id.widget_note_list_title_tv_dark, getWidgetTitle(context, displayMode, category));
                 views.setOnClickPendingIntent(R.id.widget_note_header_icon_dark, openAppI);
diff --git a/app/src/main/java/it/niedermann/owncloud/notes/android/appwidget/NoteListWidgetConfiguration.java b/app/src/main/java/it/niedermann/owncloud/notes/android/appwidget/NoteListWidgetConfiguration.java
index e73636ee..640fe8ac 100644
--- a/app/src/main/java/it/niedermann/owncloud/notes/android/appwidget/NoteListWidgetConfiguration.java
+++ b/app/src/main/java/it/niedermann/owncloud/notes/android/appwidget/NoteListWidgetConfiguration.java
@@ -100,7 +100,7 @@ public class NoteListWidgetConfiguration extends AppCompatActivity {
                 }
 
                 sp.putLong(NoteListWidget.ACCOUNT_ID_KEY + appWidgetId, localAccount.getId());
-                sp.putBoolean(NoteListWidget.DARK_THEME_KEY + appWidgetId, Notes.getAppTheme(getApplicationContext()));
+                sp.putString(NoteListWidget.DARK_THEME_KEY + appWidgetId, Notes.getAppTheme(getApplicationContext()).name());
                 sp.apply();
 
                 Intent updateIntent = new Intent(   AppWidgetManager.ACTION_APPWIDGET_UPDATE, null,
diff --git a/app/src/main/java/it/niedermann/owncloud/notes/android/appwidget/NoteListWidgetFactory.java b/app/src/main/java/it/niedermann/owncloud/notes/android/appwidget/NoteListWidgetFactory.java
index 773efdcd..0e6822e6 100644
--- a/app/src/main/java/it/niedermann/owncloud/notes/android/appwidget/NoteListWidgetFactory.java
+++ b/app/src/main/java/it/niedermann/owncloud/notes/android/appwidget/NoteListWidgetFactory.java
@@ -13,9 +13,11 @@ import android.widget.RemoteViewsService;
 import java.util.List;
 
 import it.niedermann.owncloud.notes.R;
+import it.niedermann.owncloud.notes.android.DarkModeSetting;
 import it.niedermann.owncloud.notes.android.activity.EditNoteActivity;
 import it.niedermann.owncloud.notes.model.DBNote;
 import it.niedermann.owncloud.notes.persistence.NoteSQLiteOpenHelper;
+import it.niedermann.owncloud.notes.util.Notes;
 
 public class NoteListWidgetFactory implements RemoteViewsService.RemoteViewsFactory {
     private final Context context;
@@ -32,7 +34,9 @@ public class NoteListWidgetFactory implements RemoteViewsService.RemoteViewsFact
                 AppWidgetManager.INVALID_APPWIDGET_ID);
         final SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this.context);
         displayMode = sp.getInt(NoteListWidget.WIDGET_MODE_KEY + appWidgetId, -1);
-        darkTheme = sp.getBoolean(NoteListWidget.DARK_THEME_KEY + appWidgetId, false);
+        String themeName = sp.getString(NoteListWidget.DARK_THEME_KEY + appWidgetId, DarkModeSetting.SYSTEM_DEFAULT.name());
+        DarkModeSetting theme = DarkModeSetting.valueOf(themeName);
+        darkTheme = Notes.isDarkThemeActive(context, theme);
         category = sp.getString(NoteListWidget.WIDGET_CATEGORY_KEY + appWidgetId, "");
         accountId = sp.getLong(NoteListWidget.ACCOUNT_ID_KEY + appWidgetId, -1);
     }
diff --git a/app/src/main/java/it/niedermann/owncloud/notes/android/appwidget/SingleNoteWidget.java b/app/src/main/java/it/niedermann/owncloud/notes/android/appwidget/SingleNoteWidget.java
index 0b7020d5..c1e5679b 100644
--- a/app/src/main/java/it/niedermann/owncloud/notes/android/appwidget/SingleNoteWidget.java
+++ b/app/src/main/java/it/niedermann/owncloud/notes/android/appwidget/SingleNoteWidget.java
@@ -12,8 +12,10 @@ import android.preference.PreferenceManager;
 import android.widget.RemoteViews;
 
 import it.niedermann.owncloud.notes.R;
+import it.niedermann.owncloud.notes.android.DarkModeSetting;
 import it.niedermann.owncloud.notes.android.activity.EditNoteActivity;
 import it.niedermann.owncloud.notes.android.fragment.BaseNoteFragment;
+import it.niedermann.owncloud.notes.util.Notes;
 
 public class SingleNoteWidget extends AppWidgetProvider {
 
@@ -32,7 +34,8 @@ public class SingleNoteWidget extends AppWidgetProvider {
                 return;
             }
 
-            boolean darkTheme = sp.getBoolean(DARK_THEME_KEY + appWidgetId, false);
+            String darkThemeName = sp.getString(DARK_THEME_KEY + appWidgetId, DarkModeSetting.SYSTEM_DEFAULT.name());
+            DarkModeSetting darkTheme = DarkModeSetting.valueOf(darkThemeName);
             templateIntent.putExtra(BaseNoteFragment.PARAM_ACCOUNT_ID, sp.getLong(ACCOUNT_ID_KEY + appWidgetId, -1));
 
             PendingIntent templatePendingIntent = PendingIntent.getActivity(context, appWidgetId, templateIntent,
@@ -44,7 +47,7 @@ public class SingleNoteWidget extends AppWidgetProvider {
 
             RemoteViews views;
 
-            if (darkTheme) {
+            if (Notes.isDarkThemeActive(context, darkTheme)) {
                 views = new RemoteViews(context.getPackageName(), R.layout.widget_single_note_dark);
                 views.setPendingIntentTemplate(R.id.single_note_widget_lv_dark, templatePendingIntent);
                 views.setRemoteAdapter(R.id.single_note_widget_lv_dark, serviceIntent);
diff --git a/app/src/main/java/it/niedermann/owncloud/notes/android/appwidget/SingleNoteWidgetFactory.java b/app/src/main/java/it/niedermann/owncloud/notes/android/appwidget/SingleNoteWidgetFactory.java
index 4746d026..557a83c9 100644
--- a/app/src/main/java/it/niedermann/owncloud/notes/android/appwidget/SingleNoteWidgetFactory.java
+++ b/app/src/main/java/it/niedermann/owncloud/notes/android/appwidget/SingleNoteWidgetFactory.java
@@ -14,10 +14,12 @@ import com.yydcdut.markdown.MarkdownProcessor;
 import com.yydcdut.markdown.syntax.text.TextFactory;
 
 import it.niedermann.owncloud.notes.R;
+import it.niedermann.owncloud.notes.android.DarkModeSetting;
 import it.niedermann.owncloud.notes.android.activity.EditNoteActivity;
 import it.niedermann.owncloud.notes.model.DBNote;
 import it.niedermann.owncloud.notes.persistence.NoteSQLiteOpenHelper;
 import it.niedermann.owncloud.notes.util.MarkDownUtil;
+import it.niedermann.owncloud.notes.util.Notes;
 
 public class SingleNoteWidgetFactory implements RemoteViewsService.RemoteViewsFactory {
 
@@ -28,7 +30,7 @@ public class SingleNoteWidgetFactory implements RemoteViewsService.RemoteViewsFa
     private NoteSQLiteOpenHelper db;
     private DBNote note;
     private final SharedPreferences sp;
-    private static Boolean darkTheme;
+    private static boolean darkModeActive;
 
     private static final String TAG = SingleNoteWidget.class.getSimpleName();
 
@@ -37,10 +39,11 @@ public class SingleNoteWidgetFactory implements RemoteViewsService.RemoteViewsFa
         appWidgetId = intent.getIntExtra(AppWidgetManager.EXTRA_APPWIDGET_ID,
                                          AppWidgetManager.INVALID_APPWIDGET_ID);
         sp = PreferenceManager.getDefaultSharedPreferences(this.context);
-        darkTheme = sp.getBoolean(SingleNoteWidget.DARK_THEME_KEY + appWidgetId, false);
+        String themeName = sp.getString(SingleNoteWidget.DARK_THEME_KEY + appWidgetId, DarkModeSetting.SYSTEM_DEFAULT.name());
+        darkModeActive = Notes.isDarkThemeActive(context, DarkModeSetting.valueOf(themeName));
         markdownProcessor = new MarkdownProcessor(this.context);
         markdownProcessor.factory(TextFactory.create());
-        markdownProcessor.config(MarkDownUtil.getMarkDownConfiguration(this.context, darkTheme).build());
+        markdownProcessor.config(MarkDownUtil.getMarkDownConfiguration(this.context, darkModeActive).build());
     }
 
     @Override
@@ -101,7 +104,7 @@ public class SingleNoteWidgetFactory implements RemoteViewsService.RemoteViewsFa
         extras.putLong(EditNoteActivity.PARAM_ACCOUNT_ID, note.getAccountId());
         fillInIntent.putExtras(extras);
         fillInIntent.setFlags(Intent.FLAG_ACTIVITY_NO_HISTORY);
-        if (darkTheme) {
+        if (darkModeActive) {
             note_content = new RemoteViews(context.getPackageName(), R.layout.widget_single_note_content_dark);
             note_content.setOnClickFillInIntent(R.id.single_note_content_tv_dark, fillInIntent);
             note_content.setTextViewText(R.id.single_note_content_tv_dark, markdownProcessor.parse(note.getContent()));
diff --git a/app/src/main/java/it/niedermann/owncloud/notes/android/fragment/PreferencesFragment.java b/app/src/main/java/it/niedermann/owncloud/notes/android/fragment/PreferencesFragment.java
index ac24265a..84b8820b 100644
--- a/app/src/main/java/it/niedermann/owncloud/notes/android/fragment/PreferencesFragment.java
+++ b/app/src/main/java/it/niedermann/owncloud/notes/android/fragment/PreferencesFragment.java
@@ -10,6 +10,7 @@ import androidx.preference.PreferenceFragmentCompat;
 import androidx.preference.SwitchPreference;
 
 import it.niedermann.owncloud.notes.R;
+import it.niedermann.owncloud.notes.android.DarkModeSetting;
 import it.niedermann.owncloud.notes.persistence.SyncWorker;
 import it.niedermann.owncloud.notes.util.Notes;
 
@@ -26,10 +27,10 @@ public class PreferencesFragment extends PreferenceFragmentCompat {
     public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
         addPreferencesFromResource(R.xml.preferences);
 
-        final SwitchPreference themePref = findPreference(getString(R.string.pref_key_theme));
+        final ListPreference themePref = findPreference(getString(R.string.pref_key_theme));
         assert themePref != null;
         themePref.setOnPreferenceChangeListener((preference, newValue) -> {
-            Notes.setAppTheme((Boolean) newValue);
+            Notes.setAppTheme(DarkModeSetting.valueOf((String) newValue));
             getActivity().setResult(Activity.RESULT_OK);
             getActivity().recreate();
             return true;
diff --git a/app/src/main/java/it/niedermann/owncloud/notes/util/MarkDownUtil.java b/app/src/main/java/it/niedermann/owncloud/notes/util/MarkDownUtil.java
index e9bf9285..46d665c0 100644
--- a/app/src/main/java/it/niedermann/owncloud/notes/util/MarkDownUtil.java
+++ b/app/src/main/java/it/niedermann/owncloud/notes/util/MarkDownUtil.java
@@ -36,7 +36,7 @@ public class MarkDownUtil {
      * @return RxMDConfiguration
      */
     public static Builder getMarkDownConfiguration(Context context) {
-        return getMarkDownConfiguration(context, Notes.getAppTheme(context));
+        return getMarkDownConfiguration(context, Notes.isDarkThemeActive(context));
     }
 
     public static Builder getMarkDownConfiguration(Context context, Boolean darkTheme) {
diff --git a/app/src/main/java/it/niedermann/owncloud/notes/util/Notes.java b/app/src/main/java/it/niedermann/owncloud/notes/util/Notes.java
index 75f43f05..79105661 100644
--- a/app/src/main/java/it/niedermann/owncloud/notes/util/Notes.java
+++ b/app/src/main/java/it/niedermann/owncloud/notes/util/Notes.java
@@ -3,9 +3,13 @@ package it.niedermann.owncloud.notes.util;
 import android.app.Application;
 import android.content.Context;
 import android.content.SharedPreferences;
+import android.content.res.Configuration;
 import android.preference.PreferenceManager;
+
 import androidx.appcompat.app.AppCompatDelegate;
 
+import it.niedermann.owncloud.notes.android.DarkModeSetting;
+
 public class Notes extends Application {
     private static final String DARK_THEME = "darkTheme";
 
@@ -15,16 +19,26 @@ public class Notes extends Application {
         super.onCreate();
     }
 
-    public static void setAppTheme(Boolean darkTheme) {
-        if (darkTheme) {
-            AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES);
+    public static void setAppTheme(DarkModeSetting setting) {
+        AppCompatDelegate.setDefaultNightMode(setting.getModeId());
+    }
+
+    public static DarkModeSetting getAppTheme(Context context) {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
+        String mode = prefs.getString(DARK_THEME, DarkModeSetting.SYSTEM_DEFAULT.name());
+        return DarkModeSetting.valueOf(mode);
+    }
+
+    public static boolean isDarkThemeActive(Context context, DarkModeSetting setting) {
+        if (setting == DarkModeSetting.SYSTEM_DEFAULT) {
+            return isDarkThemeActive(context);
         } else {
-            AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_NO);
+            return setting == DarkModeSetting.DARK;
         }
     }
 
-    public static boolean getAppTheme(Context context) {
-        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
-        return prefs.getBoolean(DARK_THEME, false);
+    public static boolean isDarkThemeActive(Context context) {
+        int uiMode = context.getResources().getConfiguration().uiMode;
+        return (uiMode & Configuration.UI_MODE_NIGHT_MASK) == Configuration.UI_MODE_NIGHT_YES;
     }
 }
diff --git a/app/src/main/res/values/arrays.xml b/app/src/main/res/values/arrays.xml
index cc342086..3fd107e9 100644
--- a/app/src/main/res/values/arrays.xml
+++ b/app/src/main/res/values/arrays.xml
@@ -10,6 +10,11 @@
         <item>@string/pref_value_font_size_medium</item>
         <item>@string/pref_value_font_size_large</item>
     </string-array>
+    <string-array name="darkMode_values">
+        <item>@string/pref_value_theme_light</item>
+        <item>@string/pref_value_theme_dark</item>
+        <item>@string/pref_value_theme_system_default</item>
+    </string-array>
     <string-array name="sync_values">
         <item>@string/pref_value_sync_off</item>
         <item>@string/pref_value_sync_15_minutes</item>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index ec594e6c..93c53eab 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -125,8 +125,10 @@
     <string name="pref_value_sync_15_minutes" translatable="false">15_minutes</string>
     <string name="pref_value_sync_1_hour" translatable="false">1_hour</string>
     <string name="pref_value_sync_6_hours" translatable="false">6_hours</string>
+    <string name="pref_value_theme_light" translatable="false">LIGHT</string>
+    <string name="pref_value_theme_dark" translatable="false">DARK</string>
+    <string name="pref_value_theme_system_default" translatable="false">SYSTEM_DEFAULT</string>
     <!-- These values should not be translateable. They should be migrated at some point.  -->
-    <string name="pref_value_theme_light">Light</string>
     <string name="pref_value_font_normal">Normal</string>
     <string name="pref_value_wifi_and_mobile">Sync on Wi-Fi and mobile data</string>
 
@@ -179,6 +181,12 @@
         <item>6 hours</item>
     </string-array>
 
+    <string-array name="darkmode_entries">
+        <item>Light</item>
+        <item>Dark</item>
+        <item>System Default</item>
+    </string-array>
+
     <!-- Plurals -->
     <plurals name="ab_selected">
         <item quantity="one">%d selected</item>
diff --git a/app/src/main/res/xml/preferences.xml b/app/src/main/res/xml/preferences.xml
index 9f61df31..86ce545d 100644
--- a/app/src/main/res/xml/preferences.xml
+++ b/app/src/main/res/xml/preferences.xml
@@ -11,8 +11,11 @@
         android:summary="%s"
         android:title="@string/settings_note_mode" />
 
-    <SwitchPreference
-        android:defaultValue="@string/pref_value_theme_light"
+    <ListPreference
+        android:defaultValue="@string/pref_value_theme_system_default"
+        android:entries="@array/darkmode_entries"
+        android:entryValues="@array/darkMode_values"
+        android:summary="%s"
         android:icon="@drawable/ic_brightness_2_grey_24dp"
         android:key="@string/pref_key_theme"
         android:layout="@layout/item_pref"