A victory for Republican Donald Trump, viewed as unpredictable by investors, would be expected to drive capital into the perceived security of the Japanese yen and Swiss franc. Trump has pledged to renegotiate the North American Free Trade Agreement with Mexico and Canada, a move that could damage both export-heavy nations' economies.
"The whole pro-Clinton trade in FX started to move in concert - Mexican peso, Canadian dollar, Japanese yen all went to session highs or session lows - and that's mainly because VoteCastr released projections that Florida was trending (Clinton's) way," said Boris Schlossberg, managing director of FX strategy at BK Asset Management.
"Florida has always been the main pivot in this election and the fact that she's trending strongly so far is really what it all comes down to."
The dollar rose as high as 105.19 yen, its highest against the yen since Oct. 31. It was last up 0.55 percent at 105.04 yen.
The dollar gained 0.25 percent versus the Swiss franc to 0.9766 franc.
The Canadian dollar added 0.2 percent against its U.S. counterpart and the Mexican peso rose more than 1 percent against the greenback, touching its highest since Sept. 8.
The euro fell against the dollar, retracing early gains, and was last down 0.15 percent to $1.1021. It had earlier fallen to $1.1009, its lowest against the dollar in a week.
The gains against the euro and yen helped push the dollar index, which measures the greenback against six major world currencies, to its highest level in a week.