Bundesautobahn 555 (translates from German as Federal Motorway 555, short form Autobahn 555, abbreviated as BAB 555 or A 555) is an autobahn connecting the cities of Cologne and Bonn.

Because it was the first public road that was limited to motorized vehicles and had no level crossings, it is commonly regarded as the oldest German Autobahn, even though it was only a country road at first and wasn't officially awarded Autobahn status until 1958.

Except for deceleration at each end, the A 555 did not have a speed limit, resulting in about 15 km of mostly straight three-lane-road on flat terrain, enabling motorists to drive their vehicles at top speed.

In Cologne, the A 555 spur has the by-name "Diplomatenrennbahn" (Diplomat race track), seemingly because foreign diplomats and state visitors liked to take a spin from Bonn to Cologne and back when Bonn still was the seat of government of West Germany.

Bonn locals, however, used that term for the city's central stretch of B 9 due to the large number of diplomatic missions that were clustered in the area and the higher speed limit (70km/h rather than the normal urban 50km/h) limit in that area.