Elena Viacheslavovna Dementieva (born October 15, 1981) is a retired Russian tennis player.
Dementieva won the singles gold medal at the 2008 Olympics in Beijing, having previously won the silver medal at the 2000 Olympics in Sydney.
She won 16 WTA singles titles, reached the finals of the 2004 French Open and 2004 US Open and reached seven other Grand Slam semi finals.
Dementieva was also part of the Russian team that won the 2005 Fed Cup, won the 2002 WTA Championship doubles with Janette Husárová and was the runner-up in two US Open doubles finals – in 2002 with Husárová and in 2005 with Flavia Pennetta. Dementieva achieved a career-high ranking of World No. 3, which was accomplished on 6 April 2009.
She announced her retirement on 29 October 2010, after her final match at the 2010 WTA Tour Championships. Dementieva ended her career ranked World No. 9 and between 2003 and 2010 she only ended one year, in 2007, outside the top 10.