Josh Taylor will fight Jose Carlos Ramirez in a world title unification bout on 22 May.
Scotland’s Taylor, 30, is IBF and WBA champion at super-lightweight while Mexico’s Ramirez, 28, holds the WBC and WBO belts.
Both men are unbeaten, with Ramirez having won 17 of his 26 fights by knockout and Taylor claiming 13 KOs from his 17 bouts.
“I’m excited it’s been finalised and over the line,” said Taylor.
“I can’t wait to get in there for the biggest fight of my career. Fighting for the undisputed title is something all boxers dream about.”
Ramirez said: “I look forward to making history by becoming the first boxer of Mexican descent to hold all four major world title belts.”
The venue and undercard are still to be announced.