Mayweather and his handlers also considered Barclay's Center in Brooklyn, N.Y., for the pay-per-view event.
The fight will be Mayweather's ninth in a row and 12th overall at the Las Vegas hotel and casino, which has long been a hub of big-time boxing. Mayweather lives in Las Vegas.
"I will be fighting at the best place on Earth on May 3rd … the MGM Grand. Reserve your rooms at http://mgmgrand.com," Mayweather tweeted from @FloydMayweather.
Golden Boy CEO Richard Schaefer said Barclays Center made a strong bid to host the fight. Golden Boy has staged several successful shows under an exclusive promotional deal at the arena.
"The MGM is a great atmosphere for hosting a pay-per-view event, because everything is under one roof. It's perfect. You have the arena venue, you have the hotel. The MGM is built for pay per view. … I do want to add that the Barclays Center is a first-class venue," said Schaefer, crediting Barclays Center arena executive Brett Yormark.
Mayweather, who will be defending his RING and WBC welterweight titles, has been the star of record-breaking events at the MGM.
Mayweather's last fight there, a victory over Canelo Alvarez in September, was the highest-grossing boxing event of all time with nearly $150 million in revenue reported.
"Floyd is very excited to be back at home, once again," said Mayweather Promotions CEO Leonard Ellerbe. "It's a wonderful feeling to be able to bring boxing revenue to his adopted home town of Las Vegas. Floyd takes great pride in being able to bring big business to the city, and to help so many people from all different walks of life.
"It's his home. The first thing that you see coming from the airport, you see a larger than life banner that reads, 'Home of The Champion.' He loves fighting at the MGM. He has a comfort level. He can wake up and come out of 20,000 square foot mansion, drive 12 miles down the road and go and pick up tens of millions of dollars in one night. You can drive 12 miles down the road and go get it. Who is not going to like that?"
Mayweather is 11-0 with three knockouts at the MGM, including unanimous decisions over Shane Mosley, Juan Manuel Marquez, Miguel Cotto, Jose Luis Castillo and Robert Guerrero and knockouts over Diego Corrales, Ricky Hatton and Victor Ortiz.
The MGM Grand displays a Mayweather "Home of the Champion" banners on the exterior of the building, where the fighter's past five bouts have been sellouts. That includes the Alvarez bout, which shattered gate records by generating more than $20 million.
The official weigh-in for Mayweather-Canelo at the MGM Grand Garden Arena reportedly attracted more than 12,000 fans, making it one of the biggest weigh-ins in the history of the sport.
"For Floyd, there has been nothing like his big fights at the MGM Grand in Las Vegas. I think that it's the best facility for pay per view in the world, frankly. I'm happy for the MGM, I'm happy for Maidana, and I'm glad to take Floyd back to the MGM in Las Vegas," said Schaefer.
"Floyd has a very special relationship with the MGM, I think that was ultimately the decision-maker. I know that the Barclays Center will continue to bring big championship fights to their venue as well. But on May 3, the Super Bowl of Boxing is going to be at the MGM Grand."
Floyd Mayweather Jr. at the MGM Grand in Las Vegas
Opponent Result Date
Gregorio Vargas UD 12 May 18, 2000
Diego Corrales TKO 10 Jan 20, 2001
Jose Luis Castillo UD 12 April 20, 2002
Oscar De La Hoya SD 12 May 5, 2007
Ricky Hatton TKO 10 Dec. 8, 2007
Juan Manuel Marquez UD 12 Sept. 19, 2009
Shane Mosley UD 12 May 1, 2010
Victor Ortiz KO 4 Sept. 17, 2011
Miguel Cotto UD 12 May 5, 2012
Robert Guerrero UD 12 May 4, 2013
Saul Alvarez MD 12 Sept. 14, 2013