Lee's older sister Angela (born July 8, 1996, in Vancouver) is also an MMA fighter with ONE Championship and his younger brother, Adrian (born in Waipahu), also trains in martial arts.
Lee's younger sister Victoria, who was also a mixed martial artist signed to ONE, died in 2022 at the age of 18.
1998
Christian Lee (李胜龙, 이승용, born June 21, 1998), whose full name is Christian Seung Yong Lee, is a Canadian-born American mixed martial artist who competes in the featherweight, lightweight and welterweight divisions of ONE Championship.
He is the current and two-time ONE Lightweight World Champion, as well as the current ONE Welterweight World Champion.
Currently holding both belts simultaneously, Lee is the fourth two-division champion in ONE history and holds the promotion's records for most wins (17), most finishes (16), and most knockouts (12).
2012
At the 2012 USA Pankration national championships, Lee won two national titles and one silver medal.
He also won the World Championship in the MMA division at the 2012 World Pangration Athlima Federation Championships.
Lee trains out of United MMA in Waipahu, Hawaii and Evolve MMA in Singapore, alongside his teammate and sister, Angela and her husband (and also his brother-in-law), Bruno Pucci, who also competes in ONE Championship's bantamweight division.
2015
Lee made his amateur debut in 2015 at Star Elite Cage Fighting, where he defeated Avery Sanchis via first-round submission.
At the age of 17, Lee signed with ONE Championship and made his promotional debut at ONE Championship: Spirit of Champions on December 11, 2015, earning his first career win with a 29-second TKO of David Meak.
2016
Lee followed that up by submitting Mahmoud Deab Mohamed in the first round with a kimura at ONE Championship: Clash Of Heroes on January 29, 2016.
On March 18, 2016, he earned another first-round win against Anthony Engelen at ONE Championship: Union of the Warriors with a TKO stoppage by punches and elbow in a catchweight bout.
At ONE Championship: Ascent To Power on May 6, 2016, Lee improved to 4-0 when he submitted Cary Bullos in the opening round with a brabo choke.
Lee continued his streak of first-round finishes when he stopped Rocky Batolbatol by TKO at ONE Championship: Kingdom Of Champions on May 27, 2016.
In his next match on August 13, 2016, Lee suffered his first professional defeat to rising featherweight Martin Nguyen at ONE Championship: Heroes of the World, losing in the first-round via a guillotine choke.
2017
Lee rebounded by defeating Wan Jianping with a first-round TKO at ONE Championship: Kings of Destiny on April 21, 2017.
For the first time in his career, Lee was pushed to three rounds before finally submitting Keanu Subba with an armbar at ONE Championship: Quest for Greatness on August 18, 2017.
On December 9, 2017, at ONE Championship: Warriors of the World, Lee defeated former ONE Lightweight World Champion Kotetsu Boku in the first round by TKO.
2018
Lee submitted Kazunori Yokota in the second round at ONE Championship: Visions of Victory on March 9, 2018, to clinch his fourth straight win.
After his strong run of performances, Lee would earn a title shot against ONE Featherweight World Champion Martin Nguyen at ONE Championship: Unstoppable Dreams on 18 May 2018.
Following a five-round back-and-forth battle, Lee would lose by a narrow split-decision, marking his second defeat to the Vietnamese-Australian featherweight.
Lee dropped another match against Filipino Edward Kelly at ONE Championship: Beyond the Horizon on September 8, 2018, after he was disqualified under the promotion's global martial art ruleset.
During his takedown of Kelly, Lee was judged to have used an illegal belly-to-back suplex that caused Kelly to land on his head and neck.
He got back on the win sheet against former Pancrase Lightweight Champion Kazuki Tokudome in a 73 kg catchweight bout at ONE Championship: Heart of the Lion on 9 November 2018, defeating the Japanese fighter in the first-round via TKO.
The match was added to the card on short notice after his sister Angela Lee, who was scheduled to face Xiong Jing Nan for the ONE Strawweight Championship, was forced to pull out due to a back injury.
2019
He was also the winner of the 2019 ONE Lightweight World Grand Prix.
On May 17, 2019, Lee defeated Shinya Aoki to win the ONE Lightweight World Championship for the first time.
With his older sister Angela already holding the ONE Atomweight World Championship, they became the first brother-sister pair of mixed martial arts world champions.
Their younger sister Victoria was also a mixed martial artist.
Born in Vancouver to a Chinese-Singaporean father and a South Korean-born Canadian mother, Lee moved to Hawaii when he was five years old.
As both his parents are decorated martial artists, Lee started training in the sport from a young age.
In his anticipated rematch against Edward Kelly at ONE Championship: Eternal Glory on January 19, 2019, Lee stopped Kelly via first-round TKO and pushed his overall record to 14–3.
Lee agreed to an open challenge for the title from ONE Lightweight World Champion Shinya Aoki, issued in March 2019 just after Aoki had won the lightweight title himself.
Lee, a featherweight, would be moving up a division in order to challenge for the belt.
On May 17, 2019, at ONE Championship: Enter The Dragon, Lee survived an armbar submission attempt to upset the Japanese grappling legend in the second-round via TKO finish and win his first mixed martial arts world title.
His victory also made him the youngest ever male mixed martial arts world champion, as well as the first ever brother-sister pair of world champions in the history of mixed martial arts, with his sister Angela Lee holding the ONE Atomweight Championship.
On September 26, 2019, ONE Championship Chairman and founder Chatri Sityodtong announced that Lee had accepted an offer to serve as a late-notice replacement for the injured Eddie Alvarez in the ONE Lightweight World Grand Prix Championship Final.
The match would be against Turkish finalist Saygid Guseyn Arslanaliev at ONE Championship: Century Part I on 13 October 2019, after initial replacement Filipino fighter Edouard Folayang had trouble with visa issues.
The late insertion into the event would allow Lee to fight on the same card as his sister Angela Lee, who was defending her atomweight title that night.
Lee would go on to win by unanimous decision, earning the ONE Lightweight Word Grand Prix Championship.
