Tognazzi was born in Cremona, in northern Italy but spent his youth in various localities as his father was a travelling clerk for an insurance company.

After the successful role in The Fascist (Il Federale) (1961), directed by Luciano Salce, Tognazzi became one of the most renowned characters of the so-called Commedia all'Italiana (Italian comedy style).

He worked with all the main directors of Italian cinema, including Mario Monicelli (My Friends), Marco Ferreri (La Grande Bouffe), Carlo Lizzani (La vita agra), Dino Risi, Pier Paolo Pasolini (Pigsty), Ettore Scola, Alberto Lattuada, Nanni Loy, Pupi Avati and others.

In 1981, he won the Best Male Actor Award at the Cannes Film Festival for Tragedy of a Ridiculous Man, directed by Bernardo Bertolucci.

[10] While he worked primarily in Italian cinema, Tognazzi is perhaps best remembered for his role as Renato Baldi, the gay owner of a St. Tropez nightclub, in the 1978 French comedy La Cage aux Folles which became the highest grossing foreign film ever released in the U.S. Tognazzi had various relationships during his life, being married to actresses Margarete Robsahm and later Franca Bettoia.