"We will bid for the right [to host the Games]. This will boost the development of the city," Valentina Matviyenko said in an interview with Ekho Moskvy radio.
She added that she had already discussed the issue with Leonid Tyagachyov, the president of the Russian Olympic Committee. She also said that it would be necessary to ascertain if there was support from the Russian president and government for the bid.
The St. Petersburg governor earlier told RIA Novosti that Russia's northern capital had every chance of being awarded the Olympics, "if not in 2020, then certainly by the time of the next  Games."
Matviyenko first spoke of the possibility of a bid by St. Petersburg for the 2020 Olympics after the Russian resort city of Sochi was chosen last year to host the 2014 Winter Olympic Games.
St. Petersburg earlier bid for the 2004 Summer Olympics, but was not selected as one of the five candidate cities. The Games were subsequently held in Athens, Greece.
The Summer Olympics were last held in Russia in 1980 in Moscow, but the event was marred by a U.S.-led boycott involving more than 60 countries.