The 2011 St. Petersburg Open was a tennis tournament played on indoor hard courts.

It was the 17th edition of the St. Petersburg Open, and part of the ATP World Tour 250 Series of the 2011 ATP World Tour.

It took place at the Petersburg Sports and Concert Complex in Saint Petersburg, Russia, from October 24 through October 30, 2011.

* Seeds are based on the rankings of October 17, 2011.

The following players received wildcards into the singles main draw: The following players received entry a special exempt into the singles main draw: The following players received entry from the qualifying draw: Marin Čilić defeated Janko Tipsarević 6–3, 3–6, 6–2 Colin Fleming / Ross Hutchins defeated Michail Elgin / Alexandre Kudryavtsev 6–3, 6–7(5–7), [10–8]