Tübingen Hauptbahnhof is on the rail line from Stuttgart (about an hour by regional train, with frequent connections). From Stuttgart Hauptbahnhof, ICE trains run to every German city. Stuttgart Airport is the nearest international airport, about 40 minutes north by road; from Frankfurt or Munich, allow two and a half to three hours by train.
By car, Tübingen sits just south of the A8 (E52) Stuttgart-Munich autobahn, exit at Tübingen-Reutlingen and follow the B27. Parking in the old town is restricted; use the multi-storey car parks at the edge.