William Jack
William Jack is the name of the following people:
- William Jack (Politician, 1788) (1788-1852), American politician, Congressman
- William Jack (botanist) (1795-1822) Scottish botanist
- William Jack (politician, 1892) (1892–1982), Australian politician
- William Jack (athlete) (born 1930), British sprinter
- William Brydone Jack (1817–1886), Canadian mathematician and astronomer
- William Houston Jack (1806–1844), American politician