Fossombrone (anc. Forum Sempronii), a town of central Italy, in the province of Pesaro ed Urbino, 9 m. E. S. E. of Urbino; pop. about 10,000. It is situated on the road from Fano to Rome, in a narrow valley on the Metauro. It is the seat of a bishop, and has a cathedral with many ancient inscriptions, and an old castle. The most important branch of industry is silk culture. Near here Hasdrubal was defeated by the Romans in 207 B. 0. The town was destroyed by the Goths and again by the Lombards, but rebuilt by the Mala-testas. who in the 14th century sold it to the duke of Urbino.