Sestroretsk (Russian: Сестроре́цк; Finnish: Siestarjoki; Swedish: Systerbäck) is a municipal town in Kurortny District of the federal city of St. Petersburg, Russia, located on the shores of the Gulf of Finland, the Sestra River and the Sestroretskiy Lake 34 kilometers (21 mi) northwest of St. Petersburg.

A large hospital and rehabilitation center is situated within the boundaries of the town.

In 1864, the town was transferred to Russia in exchange for a promise of compensation, supposedly in the form of access to the Arctic Ocean at Petsamo.

[6] The representative body of local self-government - the municipal council - has been operating since 28 September 1997.

The Vodoslivnyy canal runs across the town from east to west and connects the Sestroretskiy Lake with the Gulf of Finland (Baltic Sea).