Michael Vincente Gazzo was born in Hillside, New Jersey, on April 5, 1923. He attended Erwin Piscator's Dramatic Workshop at the New School on the GI Bill after being demobilized from the US Atmy Air Force after World War II.
Gazzo's first major success was as a playwright. His play about drug addiction, "A Hatful of Rain," was a success on Broadway, running for 389 performances in 1955 and 1956 and winning Ben Gazzara and Anthony Franciosa Tony award nominations as Best Actor and Best Featured Actor, respectively. However, his second (and what would prove to be his last) Broadway play, "The Night Circus," also starring Gazzara, was a flop, lasting just 7 performances in 1958.
"A Hatful of Rain" was made into a successful film by Oscar-winning director Fred Zinnemann in 1957. Franciosa won an Oscar nomination for reprising his role in the film. Gazzo turned to screenwriting, penning the Elvis Presley hoss-opera King Creole (1958). Eventually he turned back to acting, where his stocky physique and unique screech of a voice made him a first-rate character actor by the 1970s.
His biggest and best acting gig came to him when Richard S. Castellano refused to appear in The Godfather part II (1974) due to a money dispute. Castellano's character Clemenza was killed off and Gazzo was cast as Clemenza's successor in the Corleone crime family in New York. Gazzo was outstanding as the old-fashioned, unsophisticated mafioso who, believing he has been betrayed and marked for death by his don, turns state's evidence against him, only to honor the Mafia code of "omerta" in the end. Gazzo won a Best Supporting Actor Oscar nod for his performance.
Gazzo continued to work in films until his death, mostly assaying Mafia bosses and other criminal types. On film, though, he was able to break out of typecasting in his frequent television appearances and play good guys. He died of a stroke on February 14, 1995 in his hometown of Hillside, New Jersey, at the age of 71.