The 62-year-old told 15,500 people gathered to see the president that "it's time for us to truly come together and make a difference", The Hollywood Reporter said.
"When I hear someone talking about the 47 per cent that don't matter, that's unacceptable," Wonder told the crowd, before launching into a set of his greatest hits, including 'Superstition'.
Like Bruce Springsteen, Katy Perry and John Mellencamp, Wonder has been travelling around the country to get the vote for Obama.
The President also paid tribute to Wonder saying, "There may be some folks who are still undecided, just decided you wanted to hear Stevie. I can't argue with that.
"But for those of you or your friends or your neighbors, who are still trying to make up their minds, this is not just a choice between two candidates or two parties. It is a choice between two different visions of America."
After the President had finished his speech, Wonder returned to the stage for an encore. He sang a few lines from 'Signed, Sealed and Delivered' mixed with Obama's rallying call, 'Fired up, ready to go!'
The audience cheered loudly as Obama offered a few dance moves.
Before arriving in Cincinnati, Wonder made an unannounced visit to Cleveland, where he did a street concert for a small crowd of 50 people near the busy Cuyahoga County early voting site.
