SIU
SIU may mean:
- Seafarers International Union of North America, an organization of labor unions
- Segment of Independent Utility, a highway engineering term for divisions of large-scale construction projects; see Interstate 69 ยง Route description
- Shinawatra University, in Bangkok, Thailand
- S.I.U. (film), a 2011 South Korean action film
- SIU, a 2019 Vocaloid album
- Siuna Airport in Nicaragua (IATA Code)
- Slave In Utero, the pen name of Lee Jong-hui, author of the South Korean webcomic Tower of God
- Southern Illinois University, a university system in the United States
- Southern Illinois University Carbondale, the system's flagship university
- Special Investigations Unit (Ontario), a police oversight agency in Ontario, Canada
- Special Investigating Unit, South African law enforcement agency
- Symbiosis International University, a private university in India
Siu may refer to:
- Shao, a Chinese surname, sometimes transliterated as Siu
- Siu, a god-hero of Torres Strait Islander people
- Xiao (surname), a Chinese surname, sometimes transliterated as Siu
- Siu (celebration) a celebration which has become increasingly popular and was made by Cristiano Ronaldo