Born in Manhattan, he served in the United States Marines during World War II and was educated at Yale University.
He also worked as an executive for Revlon and operated his own public relations firm in New York City.
He was married 4 times to 3 women, twice to Bonnie Titley Leslie, was then widowed by Revlon executive Kay Daly, and adopted her three sons.
[1] While working for Neiman Marcus, Leslie published Dallas Public and Private: Aspects of an American City in April 1964.
He also co-authored scripts for the soap opera The Secret Storm with his sister, the actress and writer Bethel Leslie.