The Gunsmoke actor died of natural causes, according to the Los Angeles Times.
Arness starred in more than 30 different films, including a number of Gunsmoke TV movies.
Famous for his height, the actor was 6 foot, 7 inches tall.
Gunsmoke premiered on September 1955 and ran for 20 years, making it one of the longest-running primetime series ever.
It was reported in 2009 that CBS would be reviving Gunsmoke as a television show once again.
Arness was a good friend of actor John Wayne. In fact, Wayne helped Arness secure the role on Gunsmoke after turning it down himself.
Arness was the brother of Mission: Impossible actor Peter Graves, who passed away in March 2010.