The Ausserfern Railway (German: Außerfernbahn) is a cross-border railway line in the German state of Bavaria and the Austrian state of Tyrol. The single-tracked branch line starts from Kempten in Germany, before crossing into Austria just after passing through Pfronten . It then transits the Außerfern area around Reutte , before passing back into Germany in order to terminate at Garmisch-Partenkirchen.

The line provides the only rail access to Reutte and the Außerfern, albeit one that requires any journey to or from the rest of Austria to pass through German territory. The line connects with the Mittenwald Railway and the Munich–Garmisch-Partenkirchen railway at Garmisch-Partenkirchen, with the former providing a link to the Tyrolean capital of Innsbruck . It connects with the Buchloe–Lindau railway and the Neu-Ulm–Kempten railway at Kempten.