Robert Charles Bryan (born April 29, 1978) is an American former doubles world No. 1 tennis player. He has won twenty-three Grand Slam titles: 16 in men's doubles and 7 in mixed doubles. He turned professional in 1998. With his twin brother Mike, he was the world No. 1 doubles player for several years, first achieving the top ranking in September 2003. The brothers were named ATP Team of the Decade for 2000–2009. The brothers became the second men's doubles team to complete the Career Golden Slam at the 2012 Summer Olympics. Bob Bryan ended his 2018 season early with subsequent hip surgery in August 2018 due to an injury he sustained during his Madrid final retirement earlier in May 2018, which would have elevated the Bryan brothers as the oldest players back to the top of the men's doubles ranking if they were victorious. His recovery from hip surgery took around 5 months, which led his brother Mike to partner with compatriots Sam Querrey and then more successfully with Jack Sock during Bob's absence.Bob and Mike Bryan retired in August 2020. In their final two tournaments, the Bryan brothers successfully defended their title in Delray Beach, also winning the decisive rubber in a U.S. Davis Cup tie in Honolulu.