Marrubiu, Marrùbiu in sardinian language, is a comune (municipality) in the Province of Oristano in the Italian region Sardinia, located about 70 kilometres (43mi) northwest of Cagliari and about 15 kilometres (9mi) south of Oristano. As of 31 December 2004, it had a population of 5,034 and an area of 61.2 square kilometres (23.6sqmi).