Grillo was born in Savignone, a small town in the Province of Genoa, Liguria. Grillo became a comedian improvising a monologue at an audition. Two weeks later he was discovered by Italian television presenter Pippo Baudo. He participated in the variety show "Secondo Voi" for two years (1977-78). Later, in 1979, he was in "Luna Park" and "Fantastico".