William "Bill" Deller OAM (born 3 November 1943) was a leading Australian rules football field umpire in the Victorian Football League (VFL) in the 1960s, 1970s and 1980s.
Despite a severe mid-career back injury, Deller compiled an impressive record. He umpired Grand Finals in both the one and two-umpire system. Immediately after retirement he was appointed part-time VFL director of umpiring and in 1987 became full-time Australian Football League national director of umpiring. He was awarded an OAM for services to umpiring.
His umpiring career spanned from 1967 to 1981, and in total he umpired 251 games, including 20 finals matches. He umpired Grand Finals in 1972, 1976, 1978, 1979, and 1980.
Deller was inducted to the Australian Football Hall of Fame in 1996.