Sinnai, Sìnnia in Sardinian language, is a comune of the Cagliari metropolitan area in the Province of Cagliari in the Italian region Sardinia, located about 12 km northeast of Cagliari. According to 2011 census, it has 16,730 inhabitants.Sinnai borders the following municipalities: Burcei, Castiadas, Dolianova, Maracalagonis, Quartucciu, San Vito, Settimo San Pietro, Soleminis, Villasalto, Villasimius.
