Mondolfo is a comune (municipality) in the Province of Pesaro e Urbino in the Italian region Marche, located about 35 kilometres (22mi) northwest of Ancona and about 25 kilometres (16mi) southeast of Pesaro, on the Adriatic Sea. As of 31 December 2004, it had a population of 11,478 and an area of 22.7 square kilometres (8.8sqmi).