Church of the Epiphany at the Kremlin, Orthodox church in Tula Kremlin, Russia.

The Church of the Epiphany is an Orthodox place of worship standing within the Tula Kremlin fortress, featuring a central dome and decorated exterior walls. The building sits separately within the fortress complex and displays characteristic Russian religious architecture from the 1800s.

A cathedral was planned from 1817, when Alexander I's visit prompted a dedication to Alexander Nevsky; Vasily Stasov's classicist design was approved in 1821 but never built. In 1849 the churchwarden Vukol Kuzovlev and mayor Nikolai Dobrynin revived the idea as a warm Epiphany cathedral with side chapels of St Nicholas and Alexander Nevsky. Built 1855–1862 to a design by Mikhailov approved by Nicholas I, it was consecrated in 1862. Closed in 1930, it lost four of five domes and since 1989 has housed the weapons museum.

The cathedral's side chapels were dedicated to Saint Nicholas and Alexander Nevsky, and the church was consecrated in 1862. Since 1989 the building has housed a weapons museum, and in 2012 it was transferred to the Russian Orthodox Church for restoration. Visitors can see the former worship space adapted for exhibitions.

The building now houses the Tula State Museum of Weapons' exhibition and cultural centre, so visits follow museum opening arrangements rather than church services. It stands inside the Tula Kremlin; enter through the fortress walls and look for the former cathedral among the kremlin buildings. The interior was rebuilt for displays, and the heating and ventilation system installed from 1892 onwards replaced the earlier hot-air ducts.

The cathedral lost four of its five domes after being closed in 1930, when various organisations took over the building. It was not demolished, and since 1989 it has housed the Tula State Arms Museum's exhibition and cultural centre, following a major reconstruction.