Kristie Ahn's parents, mother Fay and father Don Ahn, are from South Korea. She mainly plays at tournaments of the ITF Women's Circuit , where she has won seven singles and two doubles titles so far.
She achieved her first major success in 2008 at the US Open , when she fought her way into the main draw at the age of 16 with a wildcard in qualification. In the first round she lost against the number six seeded and later world number one Dinara Safina with 3: 6 and 4: 6. The following year she took part again with a wildcard in the qualifying tournament of the US Open , but this time failed in the semifinals.
After that, she appeared on the American ITF tour only sporadically and with fluctuating performances. In 2014, she did not get past the first or second round in seven tournaments played. Instead, she focused on college sports , where she competed for Stanford at the NCAA Division I Tennis Championships 2013, but with her partner Nicole Gibbs , placed fifth, was eliminated in the first round of the doubles competition. In the following year , she moved into the round of 16 in singles, seeded three. At the American Collegiate Invitational , she reached the semifinals in 2014.
After graduating with a degree in Science, Technology and Society , she played her first full season on the ITF tour in 2015. In 2016, she played her first Grand Slam tournament outside of America, the Australian Open . As later at the French Open and US Open , she already failed in qualifying. The following year, in Monterrey , she achieved her first victory in the main draw of a WTA tournament from qualifying. In November she defeated compatriot Danielle Collins in the final of the $ 75,000 tournament in Tyler , taking her first major ITF title.
With this success she succeeded for the first time qualifying for the main draw of the Australian Open , where she was defeated by Barbora Strýcová in two sets in the first round. In 2018, Ahn also increasingly competed in the qualifying rounds of WTA tournaments, but she only reached the peloton at the beginning of the season in Sydney , but lost her opening match against Kiki Bertens there . In 2019 she was able to attract international attention again after a long time in Bogotá when, as a lucky loser, she beat the top seed Je inena Ostapenko in the first round. However, she was already defeated in the next round against a Colombian wildcard player.
After she failed to qualify again in Wimbledon and failed her first match in the main draw, she achieved her best career results by far on the hard court season in the USA. So she qualified in San José for the finals and defeated Elise Mertens in the round of 16 for the first time a top 20 player before she was eliminated in the quarter-finals by Donna Vekić . At the US Open she was rewarded for this with a wildcard for the main field and moved there for the first time in the fourth round of a Grand Slam tournament after victories over the former to-player Svetlana Kuznetsova and again Ostapenko. There she met Elise Mertens again, but this time had no chance. She ended the season in the top 100 of the world rankings for the first time after another quarter-final at the WTA tournament in Seoul .