The Diocese of Tver (Russian: Тверская епархия) is an eparchy of the Russian Orthodox Church in Tver Oblast and is one of the oldest dioceses of the Russian Orthodox Church.

The Tver diocese separated from the Polotsk diocese at the Grand Prince Yaroslav Yaroslavich no later than 1271.

Until 1928, it was called the Diocese of Tver and Kashin.

From 1928 to 1943 and from 1950 to 1990, it was the Kalinin and Kashin diocese.

On December 28, 2011, Dioceses of Bezhetsk and Rzhev were separated from Tver and Kashin, and three all formed a new Metropoly of Tver, covering all Orthodox parishes in Tver Oblast.