The Diocese of Timișoara (Latin: Dioecesis Timisoarensis; Hungarian: Temesvári Római Katolikus Püspökség) is a Latin diocese of the Catholic Church in Romania established on 5 June 1930 by Pope Pius XI.

The Diocese of Cenad, corresponding to approximately the same region, had been created in 1030 by Stephen I of Hungary.

The diocese covers the Romanian Banat—the counties of Timiș, Caraș-Severin, Arad and part of Mehedinți, of which 11.1% are Roman Catholic, with compact concentrations in the Krashovani areas near Reșița and Sânnicolau Mare.

A plurality of its adherents are Hungarian, followed by Banat Swabians, Romanians, Banat Bulgarians, Croats, Slovaks and Czechs.

It is subordinate to the Bucharest Archdiocese.