Born as Cesare Deitinger in Rome, Italy to an Austrian father and an Italian mother; he adopted Danova as his stage name after becoming an actor in Rome at the end of World War II. After the film Don Juan (1955) he immigrated to the United States. He was contracted to Metro-Goldwyn-Mayer in 1956.

His appearances include The Man Who Understood Women (1959). He tested for a part in Ben Hur, but his big break was the role of Apollodorus, Cleopatra’s personal servant, in the 1963 film Cleopatra, directed by Joseph Mankiewicz and starring Elizabeth Taylor, Richard Burton and Rex Harrison. The original script called for a major role for Danova, who was to form a trio of Cleopatra’s lovers alongside Harrison’s Caesar and Burton’s Marc Antony. Though a number of scenes featuring Taylor and Danova were shot, the script was revised and the role truncated as the Burton-Taylor affair made tabloid headlines. The following year Danova starred as Count Elmo Mancini in Viva Las Vegas as Elvis Presley’s rival for both Ann-Margret and the Las Vegas Grand Prix.

In 1967, Danova played the role of Actor in the TV series Garrison’s Gorillas. The series only ran for 26 episodes. Two of his best roles were as the neighborhood mafia Don, Giovanni Cappa, in Martin Scorsese’s Mean Streets (1973) and as the corrupt mayor of Faber, Carmine DePasto, in National Lampoon’s Animal House (1978). He appeared in three episodes of The Rifleman, and regularly appeared as a guest star on numerous television series, including Honey West; The Man from U.N.C.L.E.; Daniel Boone; Charlie’s Angels; The Love Boat; Sanford and Son; Fantasy Island; Police Story; Murder, She Wrote; Airwolf; Hunter; Maude; The Rifleman; Mannix; Night Gallery; Falcon Crest; Hart to Hart; Mission: Impossible (1988–90); and his final television appearance in 1992 as Father DiMarco on In the Heat of the Night.

Danova died of a heart attack on March 19, 1992, aged 66, at the Academy of Motion Picture Arts and Sciences headquarters in Los Angeles while attending a meeting of the Foreign Language Film committee.