As an amateur, Cullen competed in the men's middleweight event at the 2014 English National Championships.
[2] Jack Patrick Cullen was born on 7 November 1993 and grew up in Little Lever, Bolton, England.
[3] Cullen competed at the 2014 English National Championships, where he lost to Jack Langford via a points-decision 2:1 in the quarter-finals at the Echo Arena, Liverpool.
[2] Cullen won the British and Commonwealth super middleweight titles by stopping defending champion Mark Heffron in the third round of their contest at Manchester Arena on 2 September 2023.
[4][5] He lost the titles in his first defense against Zak Chelli via unanimous decision at Liverpool Arena on 20 January 2024.