The name recalls a city gate on the road to Cottbus.
'Tor' means gate: in the 18th and 19th centuries a gate in Berlin's customs wall stood here, leading out of the city towards Cottbus, until the wall was demolished in the 1860s. The spelling changed many times, from Cottbusserthor to Kottbusser Tor in 1930 – even though the town itself is written with a C. Berliners call it 'Kotti'.