The Mexibús Line III (also stylized in Arabic numbers as 3) is a bus rapid transit (BRT) line in the Mexibús system.

It operates between Chimalhuacán, in the State of Mexico and Pantitlán metro station in Iztacalco and Venustiano Carranza, in Mexico City.

It was inaugurated by the governor of the State of Mexico, Eruviel Ávila on 30 April 2013 with 29 stations.

In 2023, an extension was added from Chimalcuacán Municipality to Chicoloapan de Juárez.

The Acuitlapilco–Central de Abasto route has a different type of service and stations layout: The buses are white with red, light and dark green trim.