Suni is a comune (municipality) in the Province of Oristano in the Italian region Sardinia, located about northwest of Cagliari and about north of Oristano. As of 31 December 2010, it had a population of 1,131 and an area of .
Suni borders the following municipalities: Bosa, Flussio, Modolo, Pozzomaggiore, Sagama, Sindia, Tinnura.