British WBA world super-middleweight champion Callum Smith will fight Saul ‘Canelo’ Alvarez on 19 December.
The fight will take place in the United States, with the venue still to be confirmed.
Mexican Alvarez is seen as one of the best fighters in boxing and has held world belts in four weight divisions.
Liverpudlian Smith, 30, is unbeaten in 27 fights, defending his world title twice since winning it from George Groves in 2018.
It will be a first fight in more than a year for 30-year-old Alvarez, who has only lost once in 56 bouts – against Floyd Mayweather in 2013.
Smith’s last fight was also in November 2019, when he beat John Ryder in Liverpool.
Alvarez beat Smith’s brother Liam in 2016.
Smith’s promoter Eddie Hearn told BBC Newsbeat last week it would be “an honour” to fight a “pound-for-pound great” in Alvarez.