Born in Seoul, South Korea, An is the son of Ahn Jae-Hyung and Jiao Zhimin, both of whom were medalists in table tennis at the 1988 Summer Olympics in Seoul.
An moved to the United States in December 2005 to attend the David Leadbetter Golf Academy in Bradenton, Florida, where he was also known as Ben An.
In August 2009, at age 17, An became the youngest-ever winner of the U.S. Amateur when he defeated Ben Martin 7 & 5 in the 36-hole final at Southern Hills Country Club in Tulsa, Oklahoma. He made his PGA Tour debut in March 2010 at the Arnold Palmer Invitational, two weeks before playing in The Masters. An made the cut at the 2010 Verizon Heritage and was one shot off the lead during the second round before finishing the tournament T-59.
At the 2010 U.S. Amateur, An became the first defending champion to advance to the semifinals since Tiger Woods in 1996. After An took a 3-up lead after nine holes in his semifinal match, his opponent David Chung rallied to defeat An 1-up.
An turned professional in 2011 and earned a spot on the Challenge Tour via three stages of qualifying school.
In June 2013, An had his best finish to date on the Challenge Tour, tied for second place at the Scottish Hydro Challenge. In August 2014, he won his first Challenge Tour event at the Rolex Trophy, making An the first Korean to win on the Challenge Tour. He finished 2014 in third place in the Challenge Tour Rankings, and moved up to the European Tour.
In May 2015, he won the BMW PGA Championship at Wentworth. He was only the second player to win both the U.S. Amateur and the British PGA Championship, after Arnold Palmer.
In 2016, An played the Zurich Classic of New Orleans on an exemption, and lost a playoff at the first hole. In 2016, he earned enough money as a non-member to gain a PGA Tour card for 2016–17.2009 U.S. Amateur
PGA Tour playoff record (0–1)
CUT = missed the half-way cutMost consecutive cuts made – 2 (2016 U.S. Open – 2016 Open Championship)
Longest streak of top-10s – none
"T" indicates a tie for a place
DNP = Did not play
QF, R16, R32, R64 = Round in which player lost in match play
WD = Withdrew
"T" = Tied
Yellow background for top-10.
ProfessionalEurAsia Cup (representing Asia): 2016
World Cup (representing South Korea): 2016