Oleksandr Usyk will make his heavyweight debut against Carlos Takam at the MGM National Harbor in Maryland on May 25, live on Sky Sports.
Usyk (16-0 12KOs) was the dominant force in the cruiserweight division over the last 18 months, culminating with his commanding win over Murat Gassiev in July to become the undisputed champion and the winner of the inaugural World Boxing Super Series.
Usyk's bid to win world titles at heavyweight will begin with a test against French-Cameroonian Takam (36-5-1 28KOs).
Takam challenged Anthony Joshua for the IBF, WBA and IBO World titles in October 2017, taking the Briton ten rounds, and recently starred in a fight-of-the-year contender with Derek Chisora in July 2018.
"May 25 marks a major moment in my career when I move to the heavyweight division," said Usyk.
"At cruiserweight I did it all and became the undisputed champion and that is my goal now in the heavyweights.
"This is the ultimate challenge and it begins on May 25 against Carlos Takam. It's a tough first fight but I need to test myself against world class opposition on my new road to undisputed."
"Usyk has achieved everything in the cruiserweight division - I am ready to welcome him to the new world of heavyweight boxing," said Takam.
"I can promise that this will be a great fight and I will provide Usyk with a huge test on his heavyweight debut. I have huge ambitions of my own in the division and this fight will provide me with the chance to prove that."
"The time has come for the ultimate challenge for Oleksandr Usyk," said promoter Eddie Hearn.
"This pound-for-pound star had dominated the cruiserweight division becoming undisputed champion after just 15 fights. Now he takes the daring leap to the land of the giants as he attempts to repeat his achievements in the heavyweight division.
"Takam is the perfect test for the heavyweight debut. A big strong, all action fighter who will welcome Usyk into the fold with a heavy arsenal - be ready for fireworks on May 25!"
An announcement on the undercard and ticket sale date will be made next week.