After college, Elliot served as an assistant coach at Oregon State (1949–50) and Oklahoma (1951–55). In 1956, he took the head coaching job at Nebraska, lasting one year with a record of 4–6. The next year, he took over at California, where he remained until 1959 with a compiled record of 10–21. In 1958, he led the Golden Bears to an AAWU title and an appearance in the Rose Bowl, where they lost to Iowa.
In 1960, Elliott succeeded Ray Eliot at Illinois and was at the school until 1966. With the Illini, his record was 31–34–1, earning a Big Ten title and Rose Bowl victory over Washington during the 1963 season. A few months after the end of the 1966 season, he was forced to resign in the wake of a slush fund scandal in the athletic program. In 1973, he became head coach at Miami, where he remained for two years and compiled an 11–11 record.
Elliott served as athletic director at Miami from 1973 to 1978. In March 1978, Elliott rejoined his former boss, Bud Wilkinson, as an assistant with the NFL St. Louis Cardinals. Elliott served as Executive Director of the Pro Football Hall of Fame from 1979 to 1995 and was serving on its Board of Trustees. Elliott was also a member of the Sigma Chi Fraternity and was selected as a Significant Sig.
He died in Canton, Ohio of congestive heart failure in 2013, at the age of 86.[2]