Alan Reed , also known professionally as Alan Reed Sr. , ( August 20 , 1907 -- June 14 , 1977 ) was an American actor and voice actor , best known as the original voice of Fred Flintstone ( although Daws Butler voiced the character in the pilot ) , whom he was said to have physically resembled , on `` The Flintstones '' and various spinoff series .
Alan Reed , also known professionally as Alan Reed Sr. , ( August 20 , 1907 -- June 14 , 1977 ) was an American actor and voice actor . He was best known as the original voice of Fred Flintstone on `` The Flintstones '' .