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.
Singles main-draw entrants
Seeds
| Country | Player | Rank1 | Seed |
|---|---|---|---|
 RUS
|
Mikhail Youzhny | 29 | 1 |
 UZB
|
Denis Istomin | 34 | 2 |
 SVK
|
Martin Kližan | 46 | 3 |
 ITA
|
Fabio Fognini | 54 | 4 |
| SVK
|
Lukáš Lacko | 57 | 5 |
 TPE
|
Lu Yen-hsun | 59 | 6 |
 ESP
|
Guillermo García López | 68 | 7 |
 EST
|
Jürgen Zopp | 71 | 8 |
- 1 Seeds are based on the rankings of September 10, 2012
Other entrants
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:
Withdrawals
- Igor Andreev (right shoulder injury)
- Pablo Andújar
Aljaž Bedene- Blaž Kavčič
Mikhail Kukushkin
Retirements
- Andrey Kumantsov (dizziness)
- Paolo Lorenzi (left Achilles tendon injury)
Philipp Petzschner (knee injury)- Jürgen Zopp (back injury)
Doubles main-draw entrants
Seeds
| Country | Player | Country | Player | Rank1 | Seed |
|---|---|---|---|---|---|
 USA
|
Rajeev Ram |  SRB
|
Nenad Zimonjić | 64 | 1 |
 GBR
|
Colin Fleming | GBR
|
Ross Hutchins | 69 | 2 |
 CZE
|
František Čermák | SVK
|
Michal Mertiňák | 79 | 3 |
| GER
|
Frank Moser | GBR
|
Ken Skupski | 134 | 4 |
- Rankings are as of September 10, 2012
Other entrants
The following pairs received wildcards into the doubles main draw:
Finals
Singles
Martin Kližan defeated Fabio Fognini, 6–2, 6–3
It was Kližan's first title on the ATP World Tour.
Doubles
- Rajeev Ram / Nenad Zimonjić defeated Lukáš Lacko / Igor Zelenay 6–2, 4–6, [10–6]