With 100 percent of precincts reporting, Romney finished with 46 percent of the votes and Gingrich finished with 32 percent of the votes.
Rick Santorum finished third with 13 percent and Ron Paul placed fourth with 7 percent.
Florida is the biggest and possibly the most important state in the nominating contest. Romney also immerged with all 50 of Florida's delegates.
Romney addressed his supporters at a rally Tuesday evening. He said he was ready "to lead this party and our nation" - and turn Democratic President Barack Obama out of office.
"Mr. President, you were elected to lead, you chose to follow, and now it's time to get out of the way," the former Massachusetts governor said.
Gingrich vowed to keep fighting, saying in the long-run, the GOP isn't going to nominate a liberal Republican.
"We are going to contest every place and we are going to win and we will be in Tampa as the nominee in August," Gingrich told his supporters.
Romney seemed relaxed in his final Florida event Monday night, singing "America the Beautiful" and rarely mentioning Gingrich.
Gingrich, who was riding a wave of enthusiasm after his decisive win in South Carolina, struggled to compete with Romney's fundraising abilities, staffing and network of high-profile supporters.
Gingrich spent roughly $3 million in Florida on advertising, while Romney poured more than $14 million into ads.
"We're going to have people power defeat money power in the next six months," Gingrich told his supporters Tuesday evening.
Gingrich blames his less than stellar performance in the second debate in Florida on Romney.
"The reason I seemed flat in the second debate in Florida is that I've never seen a candidate for president that methodically dishonest. I stood there thinking, 'How can you say these things you know are falsehoods?'"
The former House speaker faces a tough road ahead. He goes into a series of states where he has little organization and must overcome steep odds to win.
Paul and Santorum ceded Florida's primary to Romney and Gingrich. They spent Tuesday campaigning across Colorado and Nevada.
Nevada has 28 delegates at stake in its caucuses, which take place Saturday.
The delegates will be divided proportionally according to caucus results. Romney heads into that race with more than three times as many convention delegates as his closet rival, Gingrich.