Sida may refer to:
- Sida (crustacean), a genus of cladoceran water fleas
- Sida (plant), a genus of flowering plants
- SIDA, Security Identification Display Area, US FAA
- Swedish International Development Cooperation Agency, a Swedish governmental agency
- Acquired Immune Deficiency Syndrome (AIDS), a disease, abbreviated as SIDA in several languages
- Two journals published by the Botanical Research Institute of Texas
- The fruit of the Coula edulis tree, also called the Gabon nut
- Amphoe Sida, a district in Nakhon Ratchasima Province, Thailand
- Sida, Sida - Nakhon Ratchasima Province, Thailand