The poll said 46 percent of likely Florida voters support Clinton, while 45 percent support Trump, well within the poll's margin of error. Libertarian Gary Johnson received 2 percent, while Green Party candidate Jill Stein got 1 percent.
Conducted from Thursday to Sunday, the poll also found that incumbent Republican U.S. Sen. Marco Rubio has a seven-point edge over Democratic challenger Patrick Murphy in a race that could help decide which party controls the Senate.
The numbers in the Clinton-Trump showdown were virtually identical to a Quinnipiac poll released Wednesday. The Connecticut-based university also released poll results Monday showing Clinton up by a narrow two-point margin in North Carolina, another key state in Tuesday's election.
In comments released with the results, Peter A. Brown, assistant director of the Quinnipiac University Poll raised the prospect of an election similar to the 2000 race, when 537 votes in Florida ultimately gave the presidency to Republican George W. Bush over Democrat Al Gore.
Political analysts widely believe that Trump needs to win Florida and North Carolina to have a shot at capturing the White House.
"There is no realistic scenario under which Trump can win the White House without those two states, while Clinton might get there without them, but it's not a road she wants to travel," Brown said in comments released with the poll results.
Both campaigns were making eleventh-hour efforts to turn out voters, with Trump slated to appear at 11 a.m. Monday in Sarasota County. Meanwhile, Vice President Joe Biden was scheduled to campaign on behalf of Clinton in Tallahassee and St. Petersburg.
As of Monday morning, more than 6.4 million Floridians had already cast ballots during in-person early voting or through voting by mail, according to numbers posted by the state Division of Elections. Democrats had cast 2,558,076 of those votes, while Republicans had cast 2,470,825. No-party voters had cast 1,236,080, and third-party voters had cast 154,179.
In-person early voting ended this weekend.
In the U.S. Senate race, the Quinnipiac poll showed Rubio leading Murphy, a congressman from Jupiter, by a margin of 50 percent to 43 percent. That is similar to a six-point margin in the Quinnipiac poll last week.
"U.S. Rep. Patrick Murphy is not getting the support a Democrat needs among women and non-white voters to overcome Sen. Marco Rubio's lead among men and white voters," Brown said.
The poll released Monday surveyed 884 likely Florida voters and had a margin of error of 3.3 percentage points.
With the marathon presidential election ready to end Tuesday, a Quinnipiac University poll released Monday showed Democrat Hillary Clinton and Republican Donald Trump remaining in a virtual tie in the critical battleground state of Florida.