The Naval cathedral of Saint Nicholas in Kronstadt (Морской Никольский собор) is a Russian Orthodox cathedral built in 1903–1913 as the main church of the Russian Navy and dedicated to all fallen seamen.

The cathedral was closed in 1929,  converted to a cinema, a House of Officers (1939) and a museum of the Navy (1980). 

The Russian Orthodox Church reinstalled the cross on the main dome in 2002 and served the first Divine Liturgy in the cathedral in 2005.

In 2013, the Patriarch of Russia, with Prime Minister Dmitriy Medvedev and his spouse attending, conducted the ceremony of grand reconsecration in the now fully restored cathedral.