Fabio Wardley has activated the rematch clause which will see him face Daniel Dubois a second time.
Dubois (23-3, 22 KOs) beat Wardley (20-1-1, 19 KOs) by stoppage in Round 11 in Manchester on May 9 to win the WBO heavyweight title.
Shortly after, promoter Frank Warren said there was a rematch clause in the contracts and Queensberry confirmed on Friday that the now former champion Wardley will look to win his belt back.
"Queensberry can confirm that Fabio Wardley has activated the rematch clause following his defeat in last week's WBO world title fight against Daniel Dubois at the Co-op Live in Manchester," a statement said.
"All parties will now work towards a rematch of their fight of the year contender for later in 2026."
The prospect of a rematch, particularly this year, has divided opinions in the sport, given the brutal nature of the first encounter.
Dubois was dropped twice, in Round 1 and Round 3, before he rallied to dominate Wardley in the later rounds.
"The boxing world knows my character, and Saturday night proved that without a shred of doubt," Wardley told Sky Sports.
"It was a fight for the ages, but I made some mistakes that I will rectify in the rematch. Congratulations to Daniel, but I'm coming for you and my belt."
After the fight, Dubois labelled both himself and Wardley as "warriors." Warren said it was the best heavyweight fight he had ever promoted.
"I think that was, for me, being involved in this business ... This is my 48th year, it was humbling to watch these two guys," Warren said.
"It was just amazing, an amazing spectacle, the crowd, atmosphere, everything about it was just great."
