Crossair Ltd. Co. for Regional European Air Transport (German: Crossair AG für europäischen Regionalluftverkehr) was a Swiss regional airline headquartered on the grounds of EuroAirport Basel Mulhouse Freiburg in Saint-Louis, Haut-Rhin, France, near Basel, Switzerland.

After taking over most of the assets of Swissair following that airline's bankruptcy in 2002, Crossair was restructured to become Swiss International Air Lines.

The name later changed to Crossair on 18 November 1978, before the beginning of scheduled services on 2 July 1979, with flights from Zürich to Nuremberg, Innsbruck and Klagenfurt.

[citation needed] After parent company SAirGroup had to apply for a debt restructuring moratorium in October 2001, it became necessary to change the entire planning.

On 31 March 2002, Swissair ceased all operations while most of its assets were taken over by Crossair which then was subsequently restructured and rebranded to become Swiss International Air Lines.