He was born in San Francisco. His father was a cellist trained in Dresden, Germany; his mother, Eva König, was born in Germany.
Friedhofer began playing cello at the age of 13. After taking lessons in harmony and counterpoint at University of California, Berkeley, he was employed as a cellist for the People's Symphony Orchestra.
In 1929, he relocated to Hollywood, where he performed as a musician for Fox Studios productions such as Sunny Side Up (1920) and Grand Canary (1934). Later, he was hired as an orchestrator for Warner Bros. and worked on over 50 films for the studio. While at Warners he was largely assigned to work with Max Steiner and, because he could speak German, Erich Wolfgang Korngold. Steiner, in particular, relied on Friedhofer's skill in turning his sketches into a full orchestral score. Despite his own strong skills, he remained in their shadow for many years.
In 1937, Friedhofer composed his first full-length film score, The Adventures of Marco Polo. Though he was still employed as an orchestrator through the '30s and into the '40s, he gradually received more assignments as a composer. In 1942, he composed the score for the film Chetniks! The Fighting Guerrillas.
In 1946, at the behest of Alfred Newman, Friedhofer was hired to compose the score for the 1946 William Wyler directed film, The Best Years of Our Lives, which earned him an Oscar for Best Original Score at the 1947 Academy Awards, beating Bernard Herrmann, Miklós Rózsa, William Walton and Franz Waxman. A new recording of the score, released in 1979 by Entr'acte Recording Society, was favorably received at the time.
Friedhofer was also nominated for other films, including The Bishop's Wife, Joan of Arc, Above and Beyond, Between Heaven and Hell, Boy on a Dolphin, An Affair to Remember, and The Young Lions.
Friedhofer, who was greatly admired by his colleagues, was also noted for his caustic, self-deprecating wit. When asked by fellow composer David Raksin as to the progress he was making on his score for Joan of Arc, he replied, "I've just started on the barbecue!". In reply to an interview by Page Cook, the film music critic at Films in Review magazine, who inquired about his place in the pantheon of film musicians, Friedhofer said, "I am just a fake giant among real pygmies."
A biographical collection of essays, letters and interviews has been edited by Linda Danly.
He died from complications of a fall in Los Angeles on May 17, 1981.
Friedhofer wrote music for 256 movies, shorts or television episodes without credit — as a music department composer of themes, additional music, stock music, incidental music or background music. He composed as a primary composer, both credited and uncredited, for 166 movies, shorts or television episodes.Outlaws (1960–61) (episodes for TV series)
Empire (1962) (TV series)
Voyage to the Bottom of the Sea (1964) (episodes for TV series)
The Guns of Will Sonnett (1967) (episodes for TV series)
I Spy (1966–68) (episodes for TV series)
Lancer (1968–69) (episodes for TV series)
My Friend Tony (1969) (episode for TV series)
The F.B.I. (1970) (episode for TV series)
Barnaby Jones (1973–78) (episodes for TV series)
Psychette: William Castle and 'Homicidal' (2002) (video short released after Friedhofer's death)