By later becoming IBF champion, he became the first British boxer in history to win both an Olympic gold medal and a professional world title.

DeGale represented Great Britain at the 2008 Summer Olympics in the Middleweight boxing event, winning the gold medal.

[6] 2007 (as a middleweight) 2008 On 2 December 2008, he agreed a deal with promoter Frank Warren to become professional along with Frankie Gavin and Billy Joe Saunders.

[9] Five more victories followed before DeGale won his first regional championship, the WBA International super-middleweight title, stopping Sam Horton in five rounds.

[10][11] The bill included fellow Olympians Frankie Gavin and Billy Joe Saunders, as well as Nathan Cleverly and Kell Brook.

[12][13] On 17 March 2011, Frank Warren announced that DeGale would defend his British title against fellow Dale Youth Boxing Club graduate and Commonwealth champion George Groves at The O2 on 21 May.

[15][16][17] DeGale was scheduled to return to action in September 2011 to challenge Polish boxer Piotr Wilczewski for his European super-middleweight title.

[21] DeGale took six months out before fighting Italian boxer Cristian Sanavia on 21 April 2012 and successfully defending his European title in Denmark.

[22][23] On 13 October, DeGale went the 12 round distance against 32-year-old French super-middleweight champion Hadillah Mohoumadi and retained his EBU title.

[24] On 8 December 2012, DeGale outpointed 35-year-old Colombian fringe contender Fulgencio Zúñiga (25–6–1, 20 KOs) in a 12-round bout to win the vacant WBC Silver super-middleweight title.

When DeGale looked to attack and go for the stoppage, the referee inadvertently separated the boxers because he thought the bell sounded to end the round.

[27] DeGale returned to the UK a month later on 8 June to defend his WBC Silver title against 38-year-old Stjepan Božić (26–6, 17 KO's) at Bluewater in Greenhithe, Kent.

[29] DeGale made two more successful defences of his WBC Silver title, the first came in November 2013 against American boxer Dyah Davis.

[30] His final defence came on 1 March 2014 at the City Academy Sports Centre in Bristol against undefeated Gevorg Khatchikian (20–0, 8 KOs).

DeGale made his first appearance under Matchroom on the undercard of the Carl Froch and George Groves rematch at Wembley Stadium on 31 May 2014.

[37][38][39] DeGale's second fight under the Matchroom banner took place at the Echo Arena in Liverpool on 22 November 2014 against former WBC world title challenger Marco Antonio Peribán (20–2–1, 13 KOs).

[48][49][50] It was announced in mid-2015 that DeGale would make his first IBF super-middleweight title defence against Romanian boxer and former world champion Lucian Bute.

[58][59] Showtime Boxing confirmed that a unification fight between DeGale and WBC champion Badou Jack (20–1–2, 12 KOs) was set for 14 January 2017.

In the post-fight press conference, Jack's promoter Floyd Mayweather Jr. complained about the result saying his fighter had done enough to win and calling the decision "bad for boxing."

[71] On fight night, Truax pulled off a huge upset in defeating DeGale and claiming the IBF super-middleweight title after 12 rounds.

[72][73][74] Days after the fight, Haymon Boxing's Tim Smith stated there indeed was an immediate rematch clause in the contract agreement.

[75] In mid February 2018, Frank Warren confirmed that rematch talks were on-going between DeGale and Truax to take place in the States.

[76] On 9 March, TGB Promotions along with Mayweather Promotions officially announced the fight as the co-main event of the card also featuring the light-middleweight unification fight Erislandy Lara vs. Jarrett Hurd at The Joint at Hard Rock Hotel and Casino in Las Vegas on 7 April 2018.

[77][78] Former two-weight world champion and analyst Paulie Malignaggi was brought in to camp to assist with his training alongside DeGale's long-time trainer Jim McDonnell.

[81][82] On 20 June 2018, promoter Warren announced that fellow British boxer Billy Joe Saunders had been booked for The O2 Arena on 15 September.

[87] DeGale stopped journeyman Fidel Muñoz Monterrosa in the round 3 to record his first stoppage win in 6 fights dating back to November 2014.

[88][89] On 3 January 2019, an official press conference took place to announce the James DeGale vs. Chris Eubank Jr. grudge match, which would take place on 23 February at The O2 Arena in London, exclusively on ITV Box Office, as part of ITV's new deal with Haymon Sports’ Premier Boxing Champions.

The rivalry between DeGale and Eubank (27–2, 21 KOs) began a few years ago, after a series of run-ins, from sparring one another in the gym to trading verbal insults across social media.

[90] The last time DeGale had fought a fellow British boxer, until that point, was the majority decision loss to George Groves in May 2011.

The possibility of the fight was first announced in November 2018 with PBC's plans to 'Invade UK Market', it was then stated a pay-per-view bout would be imminent.