Ruben was the son of Polish Jewish immigrants. He grew up on the West Side of Chicago and attended Lewis Institute but did not graduate. He was involved in theater in Chicago after leaving college. After service in the military he worked for studios and wrote for radio programs including Dinah Shore's program, George Burns and Gracie Allen's show and Fred Allen's show. He also co-wrote Milton Berle's 1947-'48 radio series with Nat Hiken.
Ruben started his TV producing and directing career in 1954 when he directed the TV series of Caesar's Hour (1954). He then directed The Phil Silvers Show (1955) and Silvers' CBS TV special, Keep in Step (1959). And then he started producing The Andy Griffith Show (1960), Gomer Pyle, U.S.M.C. (1964), The Headmaster (1969), Sanford and Son (1972), C.P.O. Sharkey (1976) and Teachers Only (1982). Aaron Ruben last did a voiceover in the videogame Buick Berle, 1954 (1995).