Acting White House chief of staff Mick Mulvaney during a press briefing called it the "best place" to hold the event.
"He's not making any money off of this," Mulvaney said.
"He probably doesn't need much help" promoting his brand, he continued.
The resort features 800 acres, four golf courses, tennis courts, a 48,000-square-foot spa and a hotel. It has a 24,079-square-foot grand ballroom.
The summit held June 10 - June 12 will bring together the world's seven largest economies: Canada, France, Germany, Italy, Japan, the United Kingdom and the U.S.
"Trump National Doral Miami offers a new generation of style, service, and exclusivity infused with the Trump standard of excellence," the resort brags on its website.
The decision comes as Trump has been criticizing former Vice President Joe Biden's son Hunter for work in Ukraine and China.
Mulvaney said the White House considered 12 sites for the summit, sent advance teams to visit 10 sites and narrowed the list to four finalists: one in Hawaii, two in Utah and the Doral resort.
"It became apparent at the end of that process that Doral was far and away, far and away the best physical facility for this meeting," according to Mulvaney.
He said Doral will put on the event "at cost," and that it will cost taxpayers less than the other three finalists.
"He has bought himself an enormous headache with his choice of this," Judge Andrew Napolitano said in reaction on "Cavuto Coast to Coast."
Mulvaney said the summit will deal with issues around global growth and challenges to the global economy.