Leach made his professional boxing debut at De Vere Whites Hotel in
Bolton on 20 September 2014, losing on points over four rounds to Bobby Jenkinson. He then went on a 14 fight undefeated run culminating in claiming his first title with a unanimous decision win over Brett Fidoe for the vacant English
bantamweight championship at
Victoria Warehouse in
Manchester on 4 May 2019. After this, Leach won three successive bouts which were all billed as eliminators for a shot at the
British super-bantamweight title, registering unanimous decision successes over Scott Allan in
Glasgow on 19 September 2019,
Qais Ashfaq in
Peterborough on 17 October 2020 and
Thomas Essomba in
Sheffield on 5 June 2021. He finally got his chance at the vacant title against unbeaten
Chris Bourke at
York Hall in London on 11 March 2022, winning via unanimous decision. His reign as champion would prove to be a short one as he lost the title in his first defense against
Liam Davies at the International Centre in
Telford on 11 June 2022. Leach was knocked to the canvas in the first round and, although he recovered to continue the fight and complete the full 12 rounds, he suffered a unanimous decision defeat. After almost 16 months out of the competitive boxing ring, Leach returned at a new weight division to face
Masood Abdulah for the vacant
Commonwealth Silver
featherweight title at York Hall on 6 October 2023. Having sustained heavy punishment throughout the contest, he retired on his stool at the end of the seventh round. Back at super-bantamweight, in what would prove to be his final fight, Leach took on
Peter McGrail for the vacant
WBA International title at the
Exhibition Centre in
Liverpool on 27 April 2024, losing by unanimous decision. He announced his retirement from professional boxing in January 2025. ==Professional boxing record==