Kevin O'Neal, the brother of Ryan O'Neal, died Saturday at 77, Fox News Digital can confirm. A spokesperson for the family told the Hollywood Reporter that Kevin died in his sleep of natural causes at his home in Thousand Oaks, California. Kevin is most known for his role on "No Time for Sergeants" in the 60s, but also appeared in one of Elvis Presley's final films, "The Trouble with Girls." In "No Time for Sergeants," Kevin portrayed Private Ben Whitledge, who was the best friend of the show's lead, Airman Will Stockdale, portrayed by Sammy Jackson.