Transdev was an international public transport group based in Issy-les-Moulineaux near Paris, France, and operating in several countries.

Originally created as Société centrale pour l'équipement du territoire in 1955 and developing transportation activities since 1973, Transdev was a subsidiary Caisse des Dépôts et Consignations, a French state-owned financial institution.

[8] Its fleet included, by its own account, 15,642 buses and water taxis, 542 subway carriages, trams and trains and 4,581 demand responsive service vehicles.

Due to the nature of franchising in France, the actual number of companies and joint ventures in the group is constantly changing.

[11] In October 2007, Transdev entered a 75/25 joint venture with Bank Nederlandse Gemeenten to purchase a 67% share in Connexxion.

[21] Some of the operations transferred were: London Sovereign, which was passed on to Veolia Transdev, would also be sold to RATP Group in April 2014.

However, the Arrow Light Rail contract to operate Nottingham Express Transit was cancelled in 2011 when Tramlink Nottingham was selected as the preferred bidder for the construction of Phase 2 of the light rail, with its final day of operation on 16 December 2011.