A mastiff is a type of dog.
Mastiff may also refer to:
Military
- HMS Mastiff, eight Royal Navy vessels serving between 1797 and 1939
- Tadiran Mastiff, a battlefield unmanned aerial vehicle (UAV) built by Tadiran Electronic Industries
- Mastiff PPV, British Army designation for the Cougar armoured fighting vehicle, with extra armour
Arts and entertainment
- Mastiff (company), an American video game company
- Mastiff (novel), a 2011 fantasy novel by Tamora Pierce
