Dido or DIDO may refer to:
- Dido (Queen of Carthage), the founder and first queen of Carthage
- Dido, Queen of Carthage, a play by Christopher Marlowe
- Dido and Aeneas, an opera by Henry Purcell, based on the play by Marlowe
- Dido (singer), a British singer and songwriter
- Dido flip, the singer's eponymous hairstyle
- Dido Elizabeth Belle, daughter of John Lindsay
- Dido (footballer), a Brazilian association football player
- Tsez people or Dido, an indigenous people of the North Caucasus
- Tsez language or Dido, their language
- DIDO (nuclear reactor), a nuclear reactor at the Atomic Energy Research Establishment at Harwell, Oxfordshire
- DIDO (optimal control), a software package to solve optimal control problems
- Philaethria dido or Scarce Bamboo Page, a butterfly of the Heliconian family
- HMS Dido, the name of seven British Royal Navy vessels
- Dido class cruiser, WWII class including 16 ships
- South Devon Railway Dido class steam locomotives (1860 - 1877)
- 209 Dido, a very large main-belt asteroid
- Dido, a planet in Doctor Who television series
- "Dido", a song on Café del Mar Aria
- Fido Dido, a cartoon character licensed to Pepsico for their 7UP brand
- DIDO (network), “distributed input distributed output” wireless network technology