William McCormack was Premier of Queensland.
William McCormack is also the name of:
- William J. McCormack (1933–2016), Chief of Police of the Metro Toronto Police
- William Jerome McCormack (1924–2013), American Prelate of Roman Catholic Church
- William J. McCormack (businessman) (1890–1965), New York City businessman
- William McCormack (cricketer) (1877–1946), Australian cricketer
- John William McCormack (1891–1980), Speaker of the United States House of Representatives