The year he turned 18, in November 2009, he turned pro in mixed martial arts with a submission win at Grachan in Japan. In 2010, he lost a split decision to Yusuke Kagiyama, his only loss before the UFC. In June 2013, he won his ninth straight international fight at a DEEP event in Japan, and in November he signed a four-fight UFC contract.
The breakthrough yearThe year he turned 23, in November, he beat Juan Manuel Puig by TKO in 18 seconds in his UFC debut in the United States, and his name became known.
In November 2015, he moved from Gumi Team Hon to Busan Team Mad and then knocked out Sam Sicilia at a UFC event in Seoul. In July 2016, he knocked out Thiago Tavares in round 1 for his third straight UFC win. That December he lost a decision to Cub Swanson, and the fight was named UFC Fight of the Year.
In 2018, he lost to Jeremy Stephens by TKO, his second straight UFC loss. In December 2019, he fought in Busan for the first time in one year and eleven months and lost to Charles Jourdain by TKO, his third straight UFC loss.
In 2021, he was moved from the long waiting list for public service worker duty to wartime labor service, which allowed him to travel abroad. A return bout set for August was cancelled because of a shoulder injury. In July 2022, he became the first Korean fighter inducted into the UFC Hall of Fame, for his 2016 fight with Cub Swanson, and in December he took his first regular variety role, on SBS’s Sunjeong Fighter.
In February 2023, in his first fight in three years and two months, he drew with Kyle Nelson. In July 2024, he beat Bill Algeo by TKO for his first UFC win in eight years. In December he beat Nate Landwehr by TKO for a second straight win.
In August 2025, a scheduled fight was cancelled because of a knee injury. In May 2026, he beat Daniel Santos by TKO for a third straight win, but in September he lost to Patricio Pitbull by KO, ending the streak.
Choi Doo-ho (born Apr 10, 1991) turned pro in mixed martial arts at Grachan in Japan on Nov 29, 2009, the year he turned 18, and became known when he won his UFC debut by TKO in 18 seconds on Nov 23, 2014, the year he turned 23. In 2022, the year he turned 31, he became the first Korean fighter inducted into the UFC Hall of Fame.
Ages are by calendar year (the year minus the birth year), birthdays aside.