Church of Saint Catherine, Orthodox church in Valday, Russia

The Church of Saint Catherine is a round, domed church built in 1793 to a design by Nikolai Lvov, with an Ionic colonnade wrapping three sides and leaving the eastern altar bay open. Its outer diameter is 21.8 m, the central hall 10.7 m, and the height with the cross about 30 m. Provincial architect I. Dmitriev replaced Lvov's Roman-Doric columns with Ionic ones and added a tall drum with a small cupola and cross.

Empress Catherine II commissioned the church, built in 1793 to a design by architect Nikolai Lvov. Provincial architect I. Dmitriev altered Lvov's plans, replacing Roman-Doric columns with Ionic ones and adding a tall drum with a cupola. In 1920 it was declared an architectural monument; after restoration in 1959–1961 it housed a museum, and since 1995 the Valday Bell Museum.

The rotunda is also called the Lvov Rotunda after its designer, architect Nikolai Lvov. Since 1995 it has housed the Valday Bell Museum, whose collection of bells is displayed inside the former church. The building no longer holds regular Orthodox services.

The rotunda stands on a hill in the town garden, between Truda Street and Komsomolsky Prospekt, a short walk from the surviving buildings of the former Travel Palace. The building is no longer an active church but houses the Valday Bell Museum, so visits follow museum opening hours. The basement can be entered from the south-west side.

The church was designed by Nikolai Lvov, but archival drawings show that provincial architect I. Dmitriev altered the plan: he replaced Roman-Doric columns with Ionic ones, added a plinth raising the height by 0.5 m, and introduced a tall drum with a small cupola and lucarnes absent from Lvov's designs.