SIW (disambiguation)

SIW or Siw may refer to:
 * Substrate-integrated waveguide, a synthetic rectangular electromagnetic waveguide formed in a dielectric substrate
 * Self-inflicted wound, the result of harming oneself
 * siw, the ISO 639 code for the Siwai language
 * SIW, the IATA code for Sibisa Airport
 * SIW, the ICAO airline code for Sirio Executive

People

 * Siw Anita Andersen (born 1966), Norwegian actress and comedian
 * Siw Malmkvist (born 1936), Swedish schlager singer and actress
 * Siw Hughes (born 1958), Welsh actress
 * Siw Wittgren-Ahl (born 1951), Swedish social democratic politician