Mondolfo is a comune (municipality) in the Province of Pesaro e Urbino in the Italian region Marche, located about 35 kilometres (22 mi) northwest of Ancona and about 25 kilometres (16 mi) southeast of Pesaro, on the Adriatic Sea.

Mondolfo borders the following municipalities: Castel Colonna, Fano, San Costanzo, Senigallia, Trecastelli. It is one of I Borghi più belli d'Italia ("The most beautiful villages of Italy").

Human presence is testified by remains from as early as the Neolithic Age. However, the first stable settlement appeared starting from the early 11th century, around a Byzantine castle existing here in the 6th-7th centuries.