SIV

SIV or Siv may refer to:


 * Simian immunodeficiency virus, a virus found in primates and related to HIV
 * Siv, a character in the children's fiction book series Guardians of Ga'Hoole
 * SIV, the IATA and FAA airport code for Sullivan County Airport, Sullivan County, Indiana, USA
 * Simulation d’incidents en vol, or simulation of flying incidents training
 * Statens Invandrarverk, the former name of Swedish immigration authority Migrationsverket (on Swedish Wikipedia)
 * Stress-induced voiding, a failure mechanism in MOSFETs
 * Structured investment vehicle, a type of fund in the shadow banking system
 * Swine influenza virus, the cause of influenza in pigs
 * Synthetic Initialization Vector, a cryptographic key-wrapping algorithm