The 2012 St. Petersburg Open was a tennis tournament played on indoor hard courts, marking the 17th edition of the St. Petersburg Open, and part of the ATP World Tour 250 Series of the 2012 ATP World Tour.

The tournament took place at the Petersburg Sports and Concert Complex in Saint Petersburg, Russia, from 17 to 23 September 2012.

Third-seeded Martin Kližan claimed the singles title.

The following players received wildcards into the singles main draw: The following players received entry from the qualifying draw: The following players received entry as lucky loser: The following pairs received wildcards into the doubles main draw: Martin Kližan defeated Fabio Fognini, 6–2, 6–3 It was Kližan's first title on the ATP World Tour.