San Teodoro is a comune (municipality) in the Province of Gallura North-East Sardinia in the Italian region Sardinia, located about 180 kilometres (110 mi) northeast of Cagliari and about 20 kilometres (12 mi) southeast of Olbia. As of 31 December 2004, it had a population of 3,565 and an area of 104.8 square kilometres (40.5 mi2).