Yuliya Andreyevna Yefimova (Russian: Юлия Андреевна Ефимова, also romanizedEfimova; born 3 April 1992) is a Russian competitive swimmer. She is the Russian national record holder in the 200 metre individual medley (short course), 50 metre breaststroke (short course and long course), 100 metre breaststroke (short course and long course), and 200 metre breaststroke (short course and long course). After making her Olympic debut in 2008, she went on to win the bronze medal in the 200 metre breaststroke in 2012, and silver medals in the 100 metre and 200 metre breaststroke in 2016. She is a six-time World Champion, winning the 50 metre breaststroke in 2009 and 2013, the 100 metre breaststroke in 2015, and the 200 metre breaststroke in 2013, 2017, and 2019. She is also a former world record holder in the 50 metre breaststroke.
After failing a drug test, Yefimova was disqualified from competition for 16 months, from October 2013 to February 2015, was stripped of her results and medals at the 2013 European Short Course Championships, and four of her world short-course records were invalidated.
Yefimova was born in Grozny, but due to the First Chechen War her family moved to Volgodonsk soon after. There she took up swimming at the age of six, coached by her father Andrey Yefimov. Until 2011, she lived in Taganrog, where she trained under Irina Vyatchanina and studied at the Southern Federal University. In March 2011, she moved to California, United States, where she was coached by Dave Salo, the head coach of the University of Southern California swimming team.
Yefimova’s first notable achievement was winning the 50 metre, 100 metre, and 200 metre breaststroke titles at the 2007 European Short Course Swimming Championships. At 15 years of age, she set her first European record and Russian national record in the short course 200 metre breaststroke with her time of 2:19.08 in the final that won her the gold medal in the event. At the 2008 European Aquatics Championships she was the gold medalist in the 200 metre breaststroke and the silver medalist in the 50 metre breaststroke. Yefimova competed at the 2008 Summer Olympics in Beijing when she was 16, placing fourth in the 100 metre breaststroke and fifth in the 200 metre breaststroke. In the prelims heats of the 100 metre breaststroke, she ranked second overall, swimming a new European record and Russian record time of 1:06.08 and finishing behind only Leisel Jones of Australia. At the 2009 World Aquatics Championships in Rome, Italy, Yefimova won the gold medal in the 50 metre breaststroke in a world record time of 30.09 seconds at 17 years of age.