Fontana was born in Arrecifies, Buenos Aires as the son of Hector and Clara Fontana. He started racing at the age of 8 at the Summer Night Championship in Lujan. In 1989, he began a full season of karting and finished 2nd in the Youth Kart Championship of Buenos Aires Province. The following year, Fontana progressed to a higher level of championship and finished 4th. In 1992, he moved into car racing and competed in the Formula Renault Argentina series before moving into the European series events in 1993.