Robbins was born Francis Kane in a New York slum and never knew his parents. He was placed in a Catholic orphanage and had several temporary foster families before finally being adopted by a pharmacist and his wife in 1927.
He made his first fortune by the age of 20, but went bankrupt in few years later. He moved to Hollywood and worked for movie studios there before publishing his first book, Never Love a Stranger, in 1948, the first of many. His novels include The Carpetbaggers (1961), The Inheritors (1969) and The Dream Merchants (1949).
He never achieved critical success, but he became wealthy through his writing and married five times.