diff --git a/qutebrowser/config/configdata.py b/qutebrowser/config/configdata.py
index c21d342e2..6d59c18df 100644
--- a/qutebrowser/config/configdata.py
+++ b/qutebrowser/config/configdata.py
@@ -951,6 +951,7 @@ KEY_DATA = collections.OrderedDict([
         ('forward', ['L']),
         ('forward -t', ['tl']),
         ('forward -w', ['wl']),
+        ('fullscreen', ['<F11>']),
         ('hint', ['f']),
         ('hint all tab', ['F']),
         ('hint all window', ['wf']),
diff --git a/qutebrowser/mainwindow/mainwindow.py b/qutebrowser/mainwindow/mainwindow.py
index 379f7b80f..a3c3fa0e4 100644
--- a/qutebrowser/mainwindow/mainwindow.py
+++ b/qutebrowser/mainwindow/mainwindow.py
@@ -305,6 +305,14 @@ class MainWindow(QWidget):
         """
         super().close()
 
+    @cmdutils.register(instance='main-window', scope='window')
+    def fullscreen(self):
+        """Toggle fullscreen mode."""
+        if self.isFullScreen():
+            self.showNormal()
+        else:
+            self.showFullScreen()
+
     def resizeEvent(self, e):
         """Extend resizewindow's resizeEvent to adjust completion.