Ellenstein passed away last week (28Oct10) of natural causes in Los Angeles, reports Variety.com.
After serving in the Army Air Corps during World War II, Ellenstein began his Hollywood career playing Quasimodo in TV programme Robert Montgomery Presents.
He had roles in 1957 action movie 3:10 to Yuma, North by Northwest, Love at First Bite and Star Trek IV: The Journey Home, playing the Federation President.
Ellenstein also racked up small-screen credits on TV series including Perry Mason, Mission: Impossible and the Wild Wild West.
He also founded The Los Angeles Academy of Stage and Cinema Arts.
The star is survived by his wife of 58 years, Lois, two sons and a daughter, as well as four grandchildren.