Bundesautobahn 656 (translates from German as Federal Motorway 656, short form Autobahn 656, abbreviated as BAB 656 or A 656) is an autobahn in Germany.

It leads from Mannheim-Neckarau to Autobahnkreuz (motorway junction) Heidelberg.

The planning for an Autobahn between Mannheim and Heidelberg began as early as 1926.

The end sections of the autobahn became part of State Highway (Bundesstrasse) B 37 in the 1990s, thus shortening the autobahn from its original 14.8 kilometres (9.2 mi) to 11.9 kilometres (7.4 mi).

At the same time, most of the crossing bridges were torn down and rebuilt with enough space to make room for an emergency lane on both sides.