Benton was born in Waxahachie, Texas, the son of Dorothy (née Spaulding) and Ellery Douglass Benton, a telephone company employee. He attended the University of Texas and Columbia University. Benton has won numerous awards for both writing and directing in film. In 1959, he co-wrote the book "The IN and OUT Book" with Harvey Schmidt, published by The Viking Press. He was the art director at Esquire magazine in the early 1960s. In 2006 he appeared in the documentary Wanderlust.
Benton's family originally came from Northumberland in the United Kingdom, where the Bentons held a seat long before the Norman Conquest of 1066. Many family members settled in America, including Abigail and Isabel Benton, who settled in Virginia in 1642; George Benton, who settled in Barbados in 1669; and Robert Benton, who settled in Virginia in 1635. Benton was once a noble family, but they were deprived of their title by the Normans after the Conquest. Robert Benton still has relatives living in England who trace their origins to the seventeenth century.