Olympic gold medallist Anthony Joshua will make his professional debut on 5 October after announcing his decision to leave the amateur code.
Joshua, 23, has not fought since his thrilling super-heavyweight Olympic win over Roberto Cammarelle.
He has signed with Eddie Hearn's Matchroom organisation and will have his first bout at London's O2 Arena.
The 6ft 6in boxer told the BBC: "My end goal is to become a world champion. An undisputed world champion."
Joshua has been plagued by a bunion problem which has kept him out of the ring since the Olympics and stopped him fighting in the European Amateur Boxing Championships in Belarus in June.
"Deep down in my heart I always wanted to become a professional. After the Games I wondered if it was the right time," he added in an interview for Saturday's BBC programme 'Inspire: The Olympic Journey'.
"A lot of the guys who turn professional after the Games rush in because it is the hype, the limelight and it is the sense of now, now, now.
"But there were a lot a things I wanted to clear up mentally.
"I thought, as an amateur, I had come to the top of the mountain and I needed to climb back down and start afresh.
"The Olympics has put me in a position to be great. To remain great is the hard thing and that is what I have to do for the next 15 years of my career."
Joshua will fight as a heavyweight in the pro game but has no plans to radically overhaul his training plans.
He said: "The formula to success as a professional is a bit different to the amateurs but is still the same discipline.
"The regime I have been on is one that has worked and the only thing I have to do is tweak it. I will not slack. I will only add to my game."
Great Britain performance director Rob McCracken said: "Anthony is a very talented sportsman who 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."
He lost to Azerbaijan fighter Magomedrasul Majidov in the final of the 2011 competition.
The full Anthony Joshua interview is on the BBC's Inspire: The Olympic Journey, which is being shown on BBC One on Saturday at 12.45 BST.