The state finished counting votes on Saturday. Mr. Obama was declared the winner, giving him a 332 to 206 final margin in the Electoral College.
Florida officials said the president had 50 percent of the vote compared to Romney's 49.1 percent, which amounts to a margin of about 74,000 votes.
Winning Florida gives Mr. Obama victories in eight of nine critical swing states, losing only North Carolina. In addition to Florida, he won Ohio, Iowa, New Hampshire, Wisconsin, Virginia, Colorado and Nevada.
The Associated Press contributed to this report.