diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 1869a74d2..7a0e0be6a 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -17,6 +17,7 @@
         android:required="false" />
 
     <application
+        android:name=".LoyaltyCardLockerApplication"
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
diff --git a/app/src/main/java/protect/card_locker/BarcodeImageWriterTask.java b/app/src/main/java/protect/card_locker/BarcodeImageWriterTask.java
index 88e62ecd4..a03a52994 100644
--- a/app/src/main/java/protect/card_locker/BarcodeImageWriterTask.java
+++ b/app/src/main/java/protect/card_locker/BarcodeImageWriterTask.java
@@ -182,4 +182,4 @@ class BarcodeImageWriterTask extends AsyncTask<Void, Void, Bitmap>
             imageView.setVisibility(View.GONE);
         }
     }
-}
\ No newline at end of file
+}
diff --git a/app/src/main/java/protect/card_locker/LoyaltyCardLockerApplication.java b/app/src/main/java/protect/card_locker/LoyaltyCardLockerApplication.java
new file mode 100644
index 000000000..c53584520
--- /dev/null
+++ b/app/src/main/java/protect/card_locker/LoyaltyCardLockerApplication.java
@@ -0,0 +1,15 @@
+package protect.card_locker;
+
+import android.app.Application;
+import android.support.v7.app.AppCompatDelegate;
+
+import protect.card_locker.preferences.Settings;
+
+public class LoyaltyCardLockerApplication extends Application {
+    public void onCreate() {
+        super.onCreate();
+
+        Settings settings = new Settings(getApplicationContext());
+        AppCompatDelegate.setDefaultNightMode(settings.getTheme());
+    }
+}
diff --git a/app/src/main/java/protect/card_locker/MainActivity.java b/app/src/main/java/protect/card_locker/MainActivity.java
index b1a0a7e0f..68b736ca1 100644
--- a/app/src/main/java/protect/card_locker/MainActivity.java
+++ b/app/src/main/java/protect/card_locker/MainActivity.java
@@ -9,11 +9,13 @@ import android.content.ClipboardManager;
 import android.content.SharedPreferences;
 import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
+import android.content.res.Configuration;
 import android.database.Cursor;
 import android.net.Uri;
 import android.os.Bundle;
 import android.support.v7.app.AlertDialog;
 import android.support.v7.app.AppCompatActivity;
+import android.support.v7.app.AppCompatDelegate;
 import android.support.v7.widget.SearchView;
 import android.support.v7.widget.Toolbar;
 import android.util.Log;
@@ -34,6 +36,7 @@ import java.util.Calendar;
 import java.util.Map;
 
 import protect.card_locker.intro.IntroActivity;
+import protect.card_locker.preferences.Settings;
 import protect.card_locker.preferences.SettingsActivity;
 
 public class MainActivity extends AppCompatActivity
@@ -89,6 +92,9 @@ public class MainActivity extends AppCompatActivity
                 MenuItem searchItem = menu.findItem(R.id.action_search);
                 searchItem.collapseActionView();
             }
+
+            // In case the theme changed
+            recreate();
         }
     }
 
@@ -335,8 +341,19 @@ public class MainActivity extends AppCompatActivity
         }
 
         WebView wv = new WebView(this);
+
+        // Set CSS for dark mode if dark mode
+        String css = "";
+        Configuration config = getResources().getConfiguration();
+        int currentNightMode = config.uiMode & Configuration.UI_MODE_NIGHT_MASK;
+        if(currentNightMode == Configuration.UI_MODE_NIGHT_YES)
+        {
+            css = "<style>body {color:white; background-color:black;}</style>";
+        }
+
         String html =
             "<meta http-equiv=\"content-type\" content=\"text/html; charset=utf-8\" />" +
+            css +
             "<img src=\"file:///android_res/mipmap/ic_launcher.png\" alt=\"" + appName + "\"/>" +
             "<h1>" +
             String.format(getString(R.string.about_title_fmt),
diff --git a/app/src/main/java/protect/card_locker/preferences/Settings.java b/app/src/main/java/protect/card_locker/preferences/Settings.java
index 4fe3c9074..f6c9fb026 100644
--- a/app/src/main/java/protect/card_locker/preferences/Settings.java
+++ b/app/src/main/java/protect/card_locker/preferences/Settings.java
@@ -5,6 +5,7 @@ import android.content.SharedPreferences;
 import android.preference.PreferenceManager;
 import android.support.annotation.IntegerRes;
 import android.support.annotation.StringRes;
+import android.support.v7.app.AppCompatDelegate;
 
 import protect.card_locker.R;
 
@@ -29,6 +30,11 @@ public class Settings
         return context.getResources().getInteger(resId);
     }
 
+    private String getString(@StringRes int keyId, String defaultValue)
+    {
+        return settings.getString(getResString(keyId), defaultValue);
+    }
+
     private int getInt(@StringRes int keyId, @IntegerRes int defaultId)
     {
         return settings.getInt(getResString(keyId), getResInt(defaultId));
@@ -39,6 +45,22 @@ public class Settings
         return settings.getBoolean(getResString(keyId), defaultValue);
     }
 
+    public int getTheme()
+    {
+        String value = getString(R.string.settings_key_theme, getResString(R.string.settings_key_system_theme));
+
+        if(value.equals(getResString(R.string.settings_key_light_theme)))
+        {
+            return AppCompatDelegate.MODE_NIGHT_NO;
+        }
+        else if(value.equals(getResString(R.string.settings_key_dark_theme)))
+        {
+            return AppCompatDelegate.MODE_NIGHT_YES;
+        }
+
+        return AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM;
+    }
+
     public int getCardTitleListFontSize()
     {
         return getInt(R.string.settings_key_card_title_list_font_size, R.integer.settings_card_title_list_font_size_sp);
diff --git a/app/src/main/java/protect/card_locker/preferences/SettingsActivity.java b/app/src/main/java/protect/card_locker/preferences/SettingsActivity.java
index 167682048..ee1bccbbb 100644
--- a/app/src/main/java/protect/card_locker/preferences/SettingsActivity.java
+++ b/app/src/main/java/protect/card_locker/preferences/SettingsActivity.java
@@ -1,9 +1,11 @@
 package protect.card_locker.preferences;
 
 import android.os.Bundle;
+import android.preference.Preference;
 import android.preference.PreferenceFragment;
 import android.support.v7.app.ActionBar;
 import android.support.v7.app.AppCompatActivity;
+import android.support.v7.app.AppCompatDelegate;
 import android.view.MenuItem;
 
 import protect.card_locker.R;
@@ -44,12 +46,35 @@ public class SettingsActivity extends AppCompatActivity
     public static class SettingsFragment extends PreferenceFragment
     {
         @Override
-        public void onCreate(Bundle savedInstanceState)
+        public void onCreate(final Bundle savedInstanceState)
         {
             super.onCreate(savedInstanceState);
 
             // Load the preferences from an XML resource
             addPreferencesFromResource(R.xml.preferences);
+
+            findPreference(getResources().getString(R.string.settings_key_theme)).setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener()
+            {
+                @Override
+                public boolean onPreferenceChange(Preference preference, Object o)
+                {
+                    if(o.toString().equals(getResources().getString(R.string.settings_key_light_theme)))
+                    {
+                        AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_NO);
+                    }
+                    else if(o.toString().equals(getResources().getString(R.string.settings_key_dark_theme)))
+                    {
+                        AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES);
+                    }
+                    else
+                    {
+                        AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM);
+                    }
+
+                    getActivity().recreate();
+                    return true;
+                }
+            });
         }
     }
 }
diff --git a/app/src/main/res/layout/loyalty_card_edit_activity.xml b/app/src/main/res/layout/loyalty_card_edit_activity.xml
index 84e2a412c..4ce3df789 100644
--- a/app/src/main/res/layout/loyalty_card_edit_activity.xml
+++ b/app/src/main/res/layout/loyalty_card_edit_activity.xml
@@ -362,7 +362,8 @@
 
                 <LinearLayout android:orientation="vertical"
                               android:layout_width="fill_parent"
-                              android:layout_height="wrap_content">
+                              android:layout_height="wrap_content"
+                              android:background="@color/inputBackground">
 
                     <LinearLayout android:orientation="horizontal"
                                   android:padding="10.0dip"
diff --git a/app/src/main/res/layout/loyalty_card_layout.xml b/app/src/main/res/layout/loyalty_card_layout.xml
index 7f80ab3ab..45ea6587a 100644
--- a/app/src/main/res/layout/loyalty_card_layout.xml
+++ b/app/src/main/res/layout/loyalty_card_layout.xml
@@ -37,7 +37,6 @@
                     android:id="@+id/store"
                     android:layout_width="wrap_content"
                     android:layout_height="wrap_content"
-                    android:textColor="?android:attr/textColorSecondary"
                     android:textSize="@dimen/storeNameTextSize"
                     android:textStyle="bold"/>
 
diff --git a/app/src/main/res/values-night/colors.xml b/app/src/main/res/values-night/colors.xml
new file mode 100644
index 000000000..766606060
--- /dev/null
+++ b/app/src/main/res/values-night/colors.xml
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Palette generated by Material IO https://material.io/color/#!/?view.left=0&view.right=0&primary.color=3F51B5&secondary.color=FFC107 -->
+<!-- Colors manually flipped to dark variants -->
+<resources>
+    <color name="colorPrimary">#3f51b5</color>
+    <color name="colorPrimaryLight">#757de8</color>
+    <color name="colorPrimaryDark">#002984</color>
+    <color name="colorSecondary">#ffc107</color>
+    <color name="colorSecondaryLight">#fff350</color>
+    <color name="colorSecondaryDark">#c79100</color>
+    <color name="colorPrimaryText">#000000</color>
+    <color name="colorSecondaryText">#ffffff</color>
+
+    <color name="inputContrastBackground">#070707</color>
+    <color name="inputBackground">#000000</color>
+    <color name="inputBorder">#222222</color>
+    <color name="inputDividerBorder">#666666</color>
+</resources>
\ No newline at end of file
diff --git a/app/src/main/res/values/settings.xml b/app/src/main/res/values/settings.xml
index fe2d9bc01..882dc2567 100644
--- a/app/src/main/res/values/settings.xml
+++ b/app/src/main/res/values/settings.xml
@@ -1,5 +1,17 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
+    <string-array name="theme_values">
+        <item>@string/settings_key_system_theme</item>
+        <item>@string/settings_key_light_theme</item>
+        <item>@string/settings_key_dark_theme</item>
+    </string-array>
+
+    <string-array name="theme_value_strings">
+        <item>@string/settings_system_theme</item>
+        <item>@string/settings_light_theme</item>
+        <item>@string/settings_dark_theme</item>
+    </string-array>
+
     <array name="letter_tile_colors">
         <item>#f16364</item>
         <item>#f58559</item>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 46edaf584..aa4298aea 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -114,6 +114,14 @@
 
     <string name="settings">Settings</string>
     <string name="settings_category_title_ui">User interface</string>
+    <string name="settings_theme">Theme</string>
+    <string name="settings_key_theme" translatable="false">pref_theme</string>
+    <string name="settings_system_theme">System theme</string>
+    <string name="settings_key_system_theme" translatable="false">system</string>
+    <string name="settings_light_theme">Light theme</string>
+    <string name="settings_key_light_theme" translatable="false">light</string>
+    <string name="settings_dark_theme">Dark theme</string>
+    <string name="settings_key_dark_theme" translatable="false">dark</string>
     <string name="settings_card_title_list_font_size">Card title list font size</string>
     <string name="settings_key_card_title_list_font_size" translatable="false">pref_card_title_list_font_size_sp</string>
     <string name="settings_card_note_list_font_size">Card note list font size</string>
diff --git a/app/src/main/res/values/styles.xml b/app/src/main/res/values/styles.xml
index d7c6cc296..e1b073e67 100644
--- a/app/src/main/res/values/styles.xml
+++ b/app/src/main/res/values/styles.xml
@@ -1,7 +1,7 @@
 <resources>
 
     <!-- Base application theme. -->
-    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
+    <style name="AppTheme" parent="Theme.AppCompat.DayNight.DarkActionBar">
         <!-- Customize your theme here. -->
         <item name="colorPrimary">@color/colorPrimary</item>
         <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
diff --git a/app/src/main/res/xml/preferences.xml b/app/src/main/res/xml/preferences.xml
index 20dad4d4d..cd573de00 100644
--- a/app/src/main/res/xml/preferences.xml
+++ b/app/src/main/res/xml/preferences.xml
@@ -6,6 +6,13 @@
     <PreferenceCategory
         android:title="@string/settings_category_title_ui">
 
+        <ListPreference
+            android:key="@string/settings_key_theme"
+            android:title="@string/settings_theme"
+            android:defaultValue="@string/settings_key_system_theme"
+            android:entries="@array/theme_value_strings"
+            android:entryValues="@array/theme_values"/>
+
         <com.vanniktech.vntnumberpickerpreference.VNTNumberPickerPreference
             android:key="@string/settings_key_card_title_list_font_size"
             android:title="@string/settings_card_title_list_font_size"