Petrozavodsk (Петрозаво́дск) or Petroskoi (in Karelian/Finnish) is the capital of the Russian Republic of Karelia, with a population of 282,900. It's located at the western shore of Lake Onego.

Petrozavodsk was founded in 1703, and has had town status since 1777.

The name in Finnish is usually Petroskoi, but during the Finnish occupation of East Karelia (in the Continuation War 1941–1944), the town was renamed Äänislinna. That name was taken from the Finnish name of Lake Onego, Ääninen.