On 12 July 2019, it was confirmed that Adeleye had turned professional under
Frank Warren's Queensberry Promotions banner. Adeleye made his professional debut on 21 December 2019, on the undercard of
Daniel Dubois against
Kyotaro Fujimoto for the vacant
WBC Silver heavyweight title at the
Copper Box Arena in London. The referee, Mark Bates, called a halt to proceedings as Adeleye defeated Lithuanian fighter Dmitrij Kalinovskij via
technical knockout (TKO) in the first round. On 10 July 2020, Adeleye returned with a second-round knockout over Matt Gordon at the BT Sport Studio in London. Adeleye's third fight was a return to the BT Sport Studio on 29 August against Phil Williams, whom Adeleye stopped in the third round, achieving his third knockout victory in a row. Adeleye fought
Fabio Wardley on the undercard of
Tyson Fury vs. Francis Ngannou in Saudi Arabia on 28 October 2023, for the vacant Commonwealth heavyweight strap, Wardley’s British championship, and Adeleye’s
WBO European heavyweight belt. He lost the fight via TKO in the seventh round which resulted in him losing his undefeated record. Adeleye was knocked down in the seventh round from a left hook, which left him flat on his back, before managing to get back up on nine seconds of the
10 count. Wardley then unleashed a barrage of punches with nothing coming back from Adeleye, resulting in the referee calling a stop to the fight, thereby declaring Wardley the winner by technical knock-out. Adeleye protested the stoppage and shoved the referee John Latham. After more than a year away from competitive action, Adeleye returned to the ring on 7 December 2024, stopping English heavyweight champion
Solomon Dacres in the first round of their fight at Wembley Arena in London. Adeleye faced
Jeamie Tshikeva for the vacant
British heavyweight title at the
Co-Op Live Arena in Manchester on 5 April 2025. He won by stoppage in the sixth round. Without making any defenses, Adeleye vacated the British title in July 2025. On 16 August 2025, he lost to
Filip Hrgović by unanimous decision in
Riyadh, Saudi Arabia, on the undercard of the
Moses Itauma vs
Dillian Whyte fight. ==Personal life==