Denniston may refer to:
- People
- Alastair Denniston, British codebreaker (1881-1961)
- John Dewar Denniston, British classical scholar (1887-1949)
- Robin Denniston, British publisher, son of Alistair (1926-2012)
- Places
- Denniston, New Zealand
- Denniston, former name of Olivehurst, California
- Denniston, Kentucky, United States
- Denniston Creek, California, United States
- Dennistoun, a district in Glasgow, Scotland