John Stephenson was an American screen and voice actor, closely associated with characters in Hanna-Barbera productions, most famously Mr. Slate in The Flintstones (starring Jean Vander Pyl and Mel Blanc). He reprised his role for the many revivals and specials that were done in the decades following. He was also the narrator of the Dragnet TV series, and did several roles in The Transformers (also starring Peter Cullen, Frank Welker, Casey Kasem, and Don Messick), including Thundercracker and Kup.
Stephenson died of Alzheimer's disease in 2015, at the age of 91.