Saul 'Canelo' Alvarez will defend his WBC and WBA world super-middleweight titles against Avni Yildirim at Hard Rock Stadium in Florida on 27 February.
The Mexican added the WBA belt to his collection in a stylish win over Britain's Callum Smith in December.
The 30-year-old has lost just once in 57 bouts and will start a heavy favourite against Turkey's Yildirim.
"Avni Yildirim is a good boxer and we will put on an exciting fight," said Alvarez, a four-weight world champion.
"I'm very glad that we are able to bring this event to Miami, a short distance from where my hero, Muhammad Ali, trained."
Yildirim, 29, has 21 wins from 23 bouts having lost to American Anthony Dirrell and Britain's Chris Eubank Jr.
His last bout - the loss to Dirrell - was in February of 2019 and his last win came in September 2018.
The bout will be the first of a two-fight deal where Alvarez - boxing's best-paid fighter - will work with British promoter Eddie Hearn.
Hearn also promotes Britain's Billy Joe Saunders, who holds the WBO belt in the 168lbs super-middleweight division.
Alvarez and 31-year-old Saunders have been linked with facing one another for over a year.
"Even in a pandemic, Saul is looking to be more active than ever and in his plan to be undisputed champion he must overcome his mandatory challengers to keep his belt," said Hearn.
"Yildirim is the first of those challenges who will be attempting to dethrone the king."