The St. Petersburg Open is a men's tennis tournament that has been held annually on the indoor hard courts of the Petersburg Sports and Concert Complex in St. Petersburg in Russia since 1995. The Swede Thomas Johansson, the Russian Marat Safin, the British Andy Murray and the Croatian Marin Cilic are the only players capable of winning the tournament more than once. The 2020 edition initially canceled due to the COVID-19 pandemic, was postponed to October and promoted to ATP 500. From 2021 it returns to the calendar as ATP 250.

It was voted by tennis players as the best tournament in the ATP Tour 250 category in 2015.