The Kochelsee Railway is a branch line in Upper Bavaria (Oberbayern), Germany, that is just under 36 km long, single-tracked and fully electrified. It is operated by the Deutsche Bahn AG as route 961 in their List of German scheduled railway routes. The Kochelseebahn branches in Tutzing from the Munich Hauptbahnhof–Garmisch-Partenkirchen main line and runs from there via Penzberg to Kochel am See by the Kochelsee that gives the line its name.