Professional career
In 2022 he signed a professional deal with Boxxer, training with SugarHill Steward.
On 3 February 2024 at Wembley Arena in London, Whittaker defeated Khalid Graidia via fifth round technical knockout.
On 31 March 2024, Whittaker fought at The O2 Arena in London on the undercard of a British heavyweight title fight between Fabio Wardley and Frazer Clarke, defeating Leon Willings via unanimous decision.
On 15 June 2024, Whittaker won the IBF International light-heavyweight title after defeating 12–0 Ezra Arenyeka by unanimous decision.
On 12 October 2024, Whittaker made his first defence of his IBF International light-heavyweight title against Liam Cameron on the undercard of Artur Beterbiev vs. Dmitry Bivol. During the bout, both boxers became entangled as Whittaker pulled Cameron towards the ropes, resulting in their tumbling out of the ring, and Whittaker being forced to withdraw due to an injury. The fight subsequently went to the judges' scorecards, as per the rules of the British Boxing Board of Control, with both boxers receiving a 58–57 score respectively as well as a 58–58 score, resulting in a split decision technical draw.
Whittaker faced Cameron in a rematch in Birmingham on 20 April 2025. He won by stoppage in the second round.
In October 2025, he signed a long-term contract with Eddie Hearn led Matchroom Boxing. A month later on 29 November, Whittaker stopped Benjamin Gavazi in the first round of their fight at the National Exhibition Centre in Birmingham to win the vacant WBC Silver light-heavyweight title.
Whittaker knocked out Braian Suarez in round one at Liverpool Arena in Liverpool on 18 April 2026.
He made his United States debut against Richard Rivera at the Barclays Center in New York City on 27 June 2026. Whittaker sent his opponent to the canvas at the end of the first round and knocked him down again early in the second round, prompting the referee to stop the fight and award him the win by technical knockout.
On 3 October 2026, he faced Conor Wallace in a final eliminator for a shot at the IBF light-heavyweight title at Utilita Arena in Birmingham, winning by unanimous decision.
Public image
Whittaker has attracted attention for his flamboyant in-ring style which often includes exaggerated feints and taunting gestures. His approach has divided opinion among boxing fans and commentators, with some describing it as entertaining and others viewing it as disrespectful to opponents and the sport. In 2023, ITV News reported that Whittaker had been criticised by some boxing fans for “making a mockery of the sport” and that others had said he “needs humbling”. Whittaker rejected the suggestion that his style was disrespectful, saying that boxing was “show business” and that he wanted to entertain paying spectators.
Some of Whittaker’s opponents have also criticised his over-the-top showmanship. Before their 2024 bout, Ezra Arenyeka said that Whittaker had “always showboated and acted silly in the ring” and argued that the behaviour made him appear arrogant, although Whittaker went on to defeat Arenyeka by unanimous decision. Ahead of their scheduled 2026 bout, Whittaker's opponent Richard Rivera said he was "not convinced" by Whittaker and claimed that Whittaker had "the boxing world fooled".
