Savannah Marshall is to make her professional debut at the multi-million Floyd Mayweather v Conor McGregor showdown.
The Hartlepool fighter will box on the undercard of the ground-breaking fight between the unbeaten boxing champion and the UFC star.
Mayweather v McGregor is scheduled for August 26 in Las Vegas.
Marshall signed a four-year deal with Mayweather Promotions last month and will be based in Nevada.
And the 2012 world champion did not even know the sensational news of her first contest until last night when it was announced on TV.
Mayweather Promotions CEO Leonard Ellerbe told Sky Sports: "Speaking of Savannah, she doesn't know this so I'll break this, she will make her pro debut on that card.
"That's breaking news.
"She doesn't know that and I haven't spoken to her about that, but that's the plan.
"We're really excited.
"She's a tremendous talent and we're very glad to welcome her into the Mayweather Promotions stable.
"She's an outstanding fighter, she's a very classy young lady, and we're very happy to be able to work with her."
Marshall, known as 'The Silent Assassin' has been one of Team GB's most successful lady boxers.
She became Britain's first women's world champion, and only the second male or female, when she struck gold in China five years ago on her 21st birthday.
The Headland ABC middleweight also won the Commonwealth Games in 2014 and is a former World Combat Games and European Union champ.
The 26-year-old became the second female fighter to sign with Mayweather, joining light-middleweight LaTondria Jones.
Ellerbe said: "She really appreciated the whole GB team taking great care of her and she's ready for the next level of progression and that's obviously turning pro.
"We're very excited. We've got some very special things planned for her in the future."
McGregor has already applied for a boxing license in Nevada and while he has never boxed professionally, he does have some amateur experience from his youth.
Mayweather retired undefeated in 49 pro fights and is widely recognised as one of the greatest boxers of all time.
The 40-year-old, known as "Pretty Boy" is the overwhelming favourite - early Las Vegas odds have him at 1-10 with McGregor 7-1.