Thornber is a surname. Notable people with the surname include:
- Catherine Thornber (c. 1813–1894), Australian headmistress
- Harry Thornber (1851–1913), British cricketer
- Kraig Thornber (born 1961), British actor, singer and choreographer
- Richard Thornber (1867–?), British footballer
- Steve Thornber (born 1965), British footballer