Marat Mikhailovich Safin (Tatar: Марат Мөбин улы Сафин, Marat Möbin ulı Safin ; Russian: Мара́т Миха́йлович (Муби́нович) Са́фин; born January 27, 1980, in Moscow) is a retired Russian tennis player. Safin won two majors and reached the world number 1 ranking during his career. He was also famous for his emotional outbursts and sometimes fiery temper on court. Safin is the older brother of current World No. 1 WTA player Dinara Safina. They are the first brother-sister tandem in tennis history to both achieve No. 1 rankings.

Safin began his professional career in 1997, and held the No. 1 world ranking for a total of 9 weeks between November 2000 and April 2001. He won his first Grand Slam title at the 2000 U.S. Open after defeating Pete Sampras, and won the 2005 Australian Open, defeating Australian Lleyton Hewitt in the final. Safin helped lead Russia to Davis Cup victories in 2002 and 2006. Despite his dislike of grass courts, he became the first Russian man to reach the semifinals of Wimbledon at the 2008 Wimbledon Championships. At the time of his final Grand Slam appearance at the US Open on 2 September 2009, Safin was No. 61 in the official world men's tennis rankings.

Safin was born in Moscow, USSR (now Russia), to Mikhail Alexeivich (Mubin Aliamtsevich) Safin and Rauza Islanova, an ethnic Tatar family. Safin describes himself as a non-practicing Muslim. He speaks Russian, English, and Spanish. His parents are former tennis players and coaches. His younger sister, Dinara Safina, is a professional tennis player and silver medalist at the 2008 Olympic games in Beijing. Safin's father managed the local Spartak Tennis Club, where Safin trained in his youth alongside several tennis players, including Anna Kournikova, Elena Dementieva, and Anastasia Myskina.