Arthur made his professional debut on 24 September 2016 at the
Manchester Arena,
Manchester, scoring a four-round
points decision victory over Andy Neylon. On 4 November 2017, he gained a
disqualification (DQ) win over Tayar Mehmed at the Bowlers Exhibition Centre in Manchester. After being repeatedly warned for spitting out his gum-shield, referee Darren Sarginson disqualified Mehmed in the fifth-round. In his sixteenth fight, with a record of 15–0 (12 KO), he faced Emmanuel Anim for the vacant
Commonwealth light-heavyweight title on 12 October 2019, at the
First Direct Arena,
Leeds. In a fight which saw Arthur go beyond six rounds for the first time in his professional career, he dropped his opponent in the fourth round en route to a
unanimous decision victory, with the judges' scorecards reading 117–111, 117–110 and 115–113. Arthur was scheduled to defend his title against
Anthony Yarde on 11 April 2020, however due to the
COVID-19 pandemic, the fight was rescheduled to 5 December 2020. On 5 December 2020, Arthur defeated Yarde via Split Decision to retain his Commonwealth light- heavyweight title and win the vacant WBO Inter-Continental light-heavyweight title. On 4 December 2021, Yarde defeated Arthur in the rematch via knockout in the fourth round. A third fight between the two took place on the undercard of
Chris Eubank Jr vs. Conor Benn at the
Tottenham Hotspur Stadium on 26 April 2025, with Yarde winning by unanimous decision. Arthur challenged
European light-heavyweight champion
Bradley Rea at
Co-op Live Arena in Manchester on 1 November 2025. He was knocked to the canvas in the second round, but recovered to eventually win via majority decision with two of the ringside judges scoring the bout 115–113 and 115–112 respectively for Arthur, while the third had it a 114–114 draw. ==Personal life==