Howard Dietz was born in New York City on September 8, 1896. He briefly studied journalism at Columbia University, and then began working in advertising. After a stint in the Navy during World War I, he returned to advertising, doing ad and publicity work for several movie firms. In 1919, he joined Goldwyn Pictures Corporation as publicity director. In 1924, he became director of advertising and publicity for MGM, a position he held for over 30 years, rising to vice-president. He devised the company symbol, Leo the Lion, and its pseudo-Latin slogan, "Ars Gratia Artis".
In 1923, Dietz wrote the lyrics for an Arthur Samuels melody called "Alibi Baby," which was a hit in W.C. Fields’ stage show, Poppy. For the next few years, Dietz collaborated on several Broadway shows, including Dear Sir (1924), with Jerome Kern, and the revue Merry-Go-Round (1927).
Many of Dietz's greatest songs were written in collaboration with composer Arthur Schwartz, with whom he first worked on The Little Show in 1929 (songs from that production included "I Guess I'll I Have to Change My Plan”). Other notable songs written by Dietz and Schwartz are "Something to Remember You By" and “The Moment I Saw You” from Three’s a Crowd (1930). “Dancing in the Dark" from The Band Wagon (1931), "Alone Together" from Flying Colors (1932), "You and the Night and the Music" from Revenge With Music (1934), "By Myself," "Triplets," and "I See Your Face Before Me" from Between the Devil (1938).
After the 1938 show, Dietz and Schwartz dissolved their partnership for over a decade and Dietz concentrated on his work for MGM, also writing material for radio and television. He collaborated with Vernon Duke in 1944 on Sadie Thompson, which introduced the song "The Love I Long For." In 1948, Dietz again teamed with Schwartz to write the score for Inside U.S.A., which featured the songs "Haunted Heart" and "Rhode Island Is Famous For You." In 1950, Dietz provided an English book and lyrics (with Garson Kanin) for the Metropolitan Opera’s production of Der Fledermaus and in 1952 provided an English book and lyrics for their production of La Boheme.
Dietz and Schwartz again worked together to write the song "That's Entertainment" for the movie version of The Band Wagon. Their last two Broadway scores were for The Gay Life (1961), which starred Barbara Cook, and Jenny (1963), which starred Mary Martin.
Dietz was the director of ASCAP from 1959 to 1961, and wrote an autobiography, "Dancing in the Dark" in 1974.
He died on July 10, 1983.