Her maskless vote didn't sit well with Americans - with the US losing more than 230,000 people to coronavirus since the pandemic began.
In photos and video taken at the centre, Trump can be seen surrounded by secret service agents, all of whom are wearing masks.
The polling centre was closed for approximately 45 minutes to accommodate Melania Trump's vote.
With its 29 electoral votes, Florida is crucial to both candidates.
Florida became the Trumps' home in late 2019 when Donald Trump decided to change his residency from New York.
Melania Trump wore a US$4500 (NZ$6719) Gucci dress to vote and was escorted out of the polling station by Wendy Sartory Link, the Palm Beach County Supervisor of Elections.
Sartory Link was wearing a mask, emblazoned with a peace signal with a US flag pattern.
Trump is likely on her way back to Washington DC to spend election night with her husband as votes are counted across the country.
Melania Trump's maskless voting controversy comes just hours after she returned to the campaign trail and accused Joe Biden of wanting Americans to "hide in fear in our basements".
Speaking in West Bend, a small city in the swing state of Wisconsin, she made clear that she shared many of her husband's views about coronavirus.
Both Donald and Melania Trump recovered from coronavirus last month after contracting the potentially deadly illness.
"Covid-19 is not a partisan issue," Melania Trump said in West Bend, before launching into a bitter attack on the Democrats, who "want to project feelings of fear and doubt purely for political reasons".
Referring to Biden's warning of a "dark winter" ahead, she said: "That is not the statement of a leader. He wants to make us hide in fear in our basements rather than work bravely within our communities to find lasting solutions."
President Trump visited a Republican National Committee office in Virginia earlier today, near Washington DC, and was also unmasked.
