Martin Kaymer (born 28 December 1984) is a German professional golfer. He became the No. 1 ranked golfer in the Official World Golf Ranking on 27 February 2011 after his runner-up finish in the WGC-Accenture Match Play Championship.
He turned professional in 2005 and made his debut on the European Tour in 2007 at the UBS Hong Kong Open. Kaymer make his first cut on the European Tour at the Singapore Masters. In the final event of his first season, the Volvo Masters, he finished in 6th place. Kaymer earned €754,691 in the 2007 season and in 41st place finished as the highest-ranked rookie on the Order of Merit, winning the Sir Henry Cotton Rookie of the Year Award.
Kaymer started 2008 by winning his first European Tour event with a wire-to-wire victory at the Abu Dhabi Golf Championship lifting him to 34th in the world rankings. The win also secured his entry into the WGC-Accenture Match Play Championship and Masters Tournament. Kaymer second victory of the year came at the BMW International Open, he became the first German to win the event in its 20-year history.
In 2009, Kaymer almost defended his title at the Abu Dhabi Golf Championship but finished tied in 2nd place, one stroke behind winner Paul Casey. In January 2010, Kaymer won the Abu Dhabi Golf Championship by one shot over Ian Poulter. On 15 August 2010, Kaymer wins the PGA Championship at Whistling Straits for his first major championship. Finishing regulation play in a two-way tie at 11 under par, he defeated Bubba Watson in a three-hole playoff.
In January 2011, Kaymer claimed his third Abu Dhabi HSBC Golf Championship title in four years and displaced Tiger Woods as number two in the world rankings. After his runner-up finish at the 2011 WGC-Accenture Match Play Championship, Kaymer overtook Lee Westwood as the number one golfer in the world, making him only the second German (after Bernhard Langer) to be the top-ranked golfer in the world. At the time he was the second youngest golfer to reach world number one behind Tiger Woods. In November 2011, Kaymer wins his first WGC title at the WGC-HSBC Champions event in Shanghai, China. On 30 September 2012, Kaymer won his singles match of the 2012 Ryder Cup against Steve Stricker by one hole. Kaymer decide to join the PGA Tour for the 2013 season. He is exempt from qualification through 2015 as a result of his 2010 PGA Championship win. In May 2014, Kaymer won The Players Championship in Ponte Vedra Beach, Florida, finishing −13 for a one-shot victory over Jim Furyk.