AAR bus+bahn was an umbrella brand of two public transport companies operating in and around the city of Aarau in the Swiss canton of Aargau.

It was launched in 2002 and comprised the Wynental- und Suhrentalbahn (WSB) and the Busbetrieb Aarau (BBA).

The two companies shared some senior managers, but remained legally distinct.

[2] With the merger of the WSB with BDWM Transport (BDWM) to form Aargau Verkehr (AVA) in 2018, the AAR bus+bahn partnership was dissolved, and AVA and BBA now operate under their own brands and with their own management teams.

[1] This article about transport in Switzerland is a stub.