Petra Klosová (born 16 April 1986) is a Czech swimmer who specialized in freestyle and backstroke events.

[1] She is a two-time Olympian and a multiple-time national champion and record holder for the freestyle and backstroke events (50, 100, and 200 m).

[2] Klosová made her first Czech team, as an eighteen-year-old, at the 2004 Summer Olympics in Athens, where she competed in the women's 4 × 100 m freestyle relay, along with her fellow swimmers Jana Myšková, Sandra Kazíková, and Ilona Hlaváčková.

[4] She challenged seven other swimmers in the third heat, including 14-year-old Sarah Sjöström of Sweden, and three-time Olympian Sherry Tsai of Hong Kong.

[5] Klosová was also a member of the SMU Mustangs swimming and diving team, and a graduate of international studies at Southern Methodist University in Dallas, Texas.