Nadezhda "Nadia" Petrova (Russian: Надежда Викторовна Петрова, Nadezhda Viktorovna Petrova); born June 8, 1982 in Moscow, Soviet Union, is a Russian professional tennis player.
She has won 27 WTA Titles, nine in singles and eighteen in doubles. In singles, Petrova has a career high ranking of World No. 3 in May 2006. She has reached the semi-finals of the French Open in 2003 and 2005. In doubles, she won the Sony Ericsson Championships in 2004 with Meghann Shaughnessy. As of 29 August 2011, Petrova was ranked World No. 30 in singles and World No. 9 in doubles.