Sia (disambiguation)
- Aeronautical Information Service
- Beau Sia
- Corsica
- Edgar Sia
- SIA Ltd
- SIA S.p.A.
- SOCO International
- Safety Investigation Authority
- Sangster International Airport
- Secret Intelligence Australia
- Securities Industry Association
- Security Industry Association
- Security Industry Authority
- Security Intelligence Agency
- Self-indication assumption
- Semiconductor Industry Association
- Service in Informatics and Analysis
- Seychelles International Airways
- Sia
- Sia (Pisidia)
- Sia (god)
- Sia (insect)
- Sia (title)
- Sia Berkeley
- Sia Figiel
- Sia Koroma
- Sia Partners
- Sia, Cyprus
- Singapore Airlines
- Smithsonian Institution Archives
- Social impact assessment
- Societe Internationale d’Acupuncture
- Society for Industrial Archeology
- Società Italiana Aviazione
- Solidaridad Internacional Antifascista
- Staten Island Academy
- Style Icon Asia
- Subaru of Indiana Automotive, Inc.
- Survivors of Incest Anonymous
- Xi'an Xiguan Airport
- Zia (disambiguation)
- Zia Pueblo, New Mexico