Harriet Frank Jr. was born and raised in Portland, Oregon, the daughter of Edith Frances (Bergman) and Sam Goldstein, a shoe store owner. Her mother changed the family name to Frank, and her own name to Harriet, making herself Harriet Sr. and her daughter Harriet Jr. In 1939, she relocated with her family to Los Angeles, where her mother worked as a Hollywood story editor; her father attended the University of California, Los Angeles (UCLA) at the same time as Irving Ravetch, her future husband. Having graduated at different times from UCLA, the two met in the Metro-Goldwyn-Mayer young writers' training program after World War II.
The couple married in 1946, but worked independently for over 10 years, with Frank writing for projects such as A Really Important Person (short, 1947), Whiplash (1948) and Run for Cover (1955). In 1953, Frank also wrote the novella The Man From Saturn, a humorous science fiction tale that first appeared in Amazing Stories magazine, and was later published as a chapbook.
The couple first collaborated on the script of an adaptation of William Faulkner's novel The Hamlet, released as The Long, Hot Summer (1958), but Frank later said "in the end, we created mostly new material, so it wasn't really a true adaptation".
