Olympic gold medallist Anthony Joshua will make his professional debut on October 5 after finally announcing his decision to turn his back on the amateur code.
Joshua has signed with Eddie Hearn's Matchroom organisation and will have his first paid outing on a show at London's O2 Arena.
Matchroom confirmed the details in a statement which read: "Anthony Joshua MBE has signed a long term promotional deal with Matchroom Sport and will make his debut at The O2 in London on October 5, live on Sky Sports."
Joshua has not fought since his thrilling countback win over Italy's Roberto Cammarelle on the final day of last summer's Games.
Joshua tweeted yesterday: "I'd like 2 thank Finchley ABC & I'd also like to thank @gbboxing for everything they have done for me. The time is upon us!"
The British Amateur Boxing Association said in a statement: "[BABA] has confirmed that the 2012 Olympic super-heavyweight gold medallist, Anthony Joshua MBE, will not be part of the GB Boxing squad in the 2013-17 Rio cycle.
"His contract with the BABA finished at the end of the 2009-2013 London Olympic cycle and he has now left the World Class Performance Programme to pursue other career opportunities."
Great Britain performance director Rob McCracken said: "Anthony is a very talented sportsman who has enjoyed a meteoric rise to become Olympic champion, less than four years after he first began boxing.
"Naturally, it is a disappointment for us that Anthony has decided his future lies away from the GB Boxing programme, but he departs with our very best regards and we wish him every success in his future career."
Joshua had been training at the Great Britain squad's gym at the English Institute of Sport in Sheffield while he considered his options in the wake of his Olympic triumph.
They included interest from both Matchroom – who recently signed Joshua's fellow gold medallist Luke Campbell – and Oscar De La Hoya's Golden Boy organisation in the United States.
Great Britain chiefs had harboured the increasingly slim hope that Joshua would elect to stay amateur and sign up instead for the new APB series run by world governing body AIBA. But the recent axing of the British Lionhearts franchise from the World Series of Boxing effectively ended any possibility of Joshua deciding to remain in the amateur ranks.
Furthermore, the Amateur Boxing Association of England is currently under a provisional suspension by AIBA, leaving England boxers' future participation in major tournaments in doubt.
Joshua will not be short of future targets in a burgeoning domestic heavyweight division headed by Haye and Fury.
But Joshua's new backers will be keen not to rush him through the ranks. Joshua is be the fourth member of Great Britain's 2012 Olympic boxing team to turn professional, following Campbell, middleweight bronze medallist Anthony Ogogo, and Thomas Stalker.
He also follows the example of five former Olympic super-heavyweight champions, and will be keen to follow the examples set by Lennox Lewis and Wladimir Klitschko rather than the 2000 gold medallist Audley Harrison.
BABA chief executive Matthew Holt said: "Like other boxers that have represented their country superbly in recent years, Anthony will remain part of the GB Boxing family and will always receive a warm welcome at our training facility in Sheffield."