SIU

SIU or Siu may mean:

• Shao, a Chinese surname, sometimes transliterated as Siu
• Xiao (surname), a Chinese surname, sometimes transliterated as Siu
• Siu, a god-hero of Torres Strait Islander people
• Slave In Utero, the pen name of Lee Jong-hui, author of the South Korean webcomic Tower of God

• Scotland in Union, a Scottish Unionist advocacy group
• Seafarers International Union of North America, an organization of labor unions
• Shinawatra University, in Bangkok, Thailand
• Special Investigating Unit, South African law enforcement agency
• Symbiosis International University, a private deemed university in India
• Southern Illinois University, a university system in the United States
  • Southern Illinois University Carbondale, the system's flagship university

• S.I.U. (film), a 2011 South Korean action film
• SIU, a 2019 Vocaloid album

• Siuna Airport in Nicaragua (IATA Code)
• Segment of Independent Utility, a highway engineering term for divisions of large-scale construction projects; see Interstate 69 § Route description

• Siuuu a celebration which has become increasingly popular and was made by Cristiano Ronaldo

• Special Investigations Unit