World Championship silver medallist Jason Quigley has signed as a professional with Golden Boy Promotions.
Quigley also won the European middleweight title as an amateur and had been linked with turning pro following a hugely successful year in 2013.
Speculation intensified recently that the 22-year-old was going to join the pro game after he opted not to defend his national title in February.
Golden Boy was founded by legendary pugilist Oscar De La Hoya and boasts some of the star names of boxing on its books.
The Donegal boxer told Sky Sports: "I'm really, really excited.
"I've been contemplating whether to make this move or not, but I've gone with this feeling in my heart that I have the excitement and hunger to go on and fulfil my childhood dreams of becoming a world professional champion."