The year he turned 23, he made his professional MMA debut. That September, he announced his retirement for financial reasons after a win. In 2006, he returned to MMA with a fight at DEEP in Japan. In August 2007, he beat DEEP welterweight champion Hidehiko Hasegawa by TKO, then drew with him in a title rematch.
The breakthrough yearIn January 2008, the year he turned 27, he became the first Korean to sign with the UFC. That May, he beat Jason Tan at UFC 84 in Las Vegas, the first Korean to win in the UFC.
In 2009, he beat T.J. Grant at UFC 100 for his third straight win. In 2010, he beat Amir Sadollah by decision at UFC 114 to make it four straight. In January 2011, he beat Nate Diaz by decision for his fifth straight win. That July, he lost to Carlos Condit by TKO, ending the streak. That December, he beat Sean Pierson for his sixth UFC win.
In 2012, he lost by TKO to Demian Maia after an injury. In 2013, he knocked out Erick Silva for his ninth UFC win.
In 2014, he knocked out John Hathaway with a spinning elbow, the first Korean fighter with 10 UFC wins. That August, he lost to Tyron Woodley by first-round KO. In 2015, he beat Josh Burkman by submission. That November, he beat Dominic Waters by TKO at the first UFC event held in Seoul.
In 2016, he beat Tarec Saffiedine by decision at UFC 207 for his 13th UFC win. In June 2017, the year he turned 36, he lost to Colby Covington by decision, his last UFC fight. In January 2018, he appeared on Please Take Care of My Refrigerator and said he wanted to move into entertainment shows after retiring. That September, he married his partner of 11 years.
In 2019, his first son was born. In 2020, he won an Excellence Award in Show/Variety at the SBS Entertainment Awards for work including Master in the House. In 2021, his second child, a daughter, was born. In 2022, he co-hosted Channel A’s Steel Ball–Dodgeball War with Kim Sung-joo.
In 2023, his third child, a daughter, was born. In November 2024, he competed at the Hanpass Invitational grappling event, his first official combat sports match since his last UFC fight. In October 2025, he competed at the Quintet 5 grappling event in Dubai and drew. In 2026, his fourth child, a son, was born, making him a father of two sons and two daughters.
Dong Hyun Kim (born Nov 17, 1981) made his professional MMA debut in 2004, the year he turned 23, and became known when he won at UFC 84 on May 25, 2008, the year he turned 27, the first Korean to win in the UFC. He fought in the UFC for the last time in 2017 and now works as a TV host.
Ages are by calendar year (the year minus the birth year), birthdays aside.