Dempsey is an inductee of both the AFL Northern Territory and the West Australian Football Halls of Fame.
Playing either as a ruckman or resting in defence – late in 1967 Bob Spargo used him successfully as a substitute for Brian France at centre half-back after the latter suffered a career-ending knee injury[5] – Dempsey became a regular in the West Perth side, winning the Breckler Medal as the club's best and fairest in 1966 and playing in premierships in 1969 and 1971.
[4] Dempsey was made a Member of the Order of the British Empire (MBE) in June 1976, for "services to sport", along with teammate Mel Whinnen.
[14] Dempsey's grandson, Malcolm Rosas Jr, is an AFL player for the Gold Coast Suns.
2 Buffaloes changed its name to the Darwin Football Club for the 1962–63 season, having previously been known as Warriors (1917–18) and Vesteys (1918–26).