2012 St. Petersburg Open – Singles

Marin Čilić was the defending champion but chose not to compete.

Martin Kližan won his first ATP World Tour title by defeating Fabio Fognini in the final, 6–2, 6–3.

Seeds
• # 🇷🇺 Mikhail Youzhny (semifinals)

• # 🇺🇿 Denis Istomin (first round)

• # 🇸🇰 Martin Kližan (champion)

• # 🇮🇹 Fabio Fognini (final)

• # 🇸🇰 Lukáš Lacko (first round)

• # Lu Yen-hsun (first round)

• # 🇪🇸 Guillermo García-López (quarterfinals)

• # 🇪🇪 Jürgen Zopp (second round, retired due to back injury)

Seeds
• # 🇷🇺 Andrey Kumantsov (qualified)

• # 🇺🇦 Stanislav Poplavskyy (second round)

• # 🇷🇺 Ivan Nedelko (qualifying competition, lucky loser)

• # 🇧🇾 Sergey Betov (qualified)

• # 🇷🇺 Mikhail Fufygin (second round)

• # 🇧🇾 Egor Gerasimov (second round)

• # 🇬🇧 Morgan Phillips (qualifying competition)

• # 🇷🇺 Anton Zaitsev (second round)

Qualifiers
• # 🇷🇺 Andrey Kumantsov

• # 🇧🇾 Nikolai Fidirko

• # 🇧🇾 Andrei Vasilevski

• # 🇧🇾 Sergey Betov

Lucky loser

 * 1) 🇷🇺 Ivan Nedelko