- Sir
- Sir Killalot
- Siralanomode
- Siralos
- Siren (The Curse of the Black Spot)
- Siren (disambiguation)
- Siren (mythology)
- Siren lamp
- Sirens of Ceres (TV story)
- Sirens of Time
- Sirgwain
- Sirgwain and the Green Knight (short story)
- Siri
- Siri O'Neal
- Sirian
- Siridih
- Sirine Saba
- Siris
- Sirithgow
- Sirius
- Sirius 5
- Sirius Alpha
- Sirius Conglomerate
- Sirius Exhibition Station
- Sirius IV
- Sirius VII
- Sirius system
- Siros
- Sirus
- Siryo