BFM TV reported the court gave Damien T, 28, a sentence of 18 months in jail. However, 14 of those months were suspended.
Earlier, he told the court in Valence in southern France, that he was a right-wing sympathiser who acted because the president stood for all he thought was wrong with France.
T attacked Macron when the French president was shaking hands with members of the public during a walkabout in France’s Drome region.
T said that several days ahead of Macron’s visit to the region, he had thought about throwing an egg or a cream tart at the president.
But he added the slap was not premeditated.
BFM TV reported T told the court: “I think that Macron represents very neatly the decay of our country.
“If I had challenged Macron to a duel at sunrise, I doubt he would have responded.”