Fermo (anc. Firmum Picenum), a town of Italy, in the province of Ascoli, 32 m. S. E. of Ancona, and 3 m. from the Adriatic; pop. about 20,000. It is the seat of an archbishop, has a cathedral and seven other churches, a lyceum, a communal gymnasium, a public library, and a theatre. It exports corn, silk, and woollens. It was founded by the Sabines before Rome existed, and became in 264 B. C. a Roman colony. From the 8th century it generally belonged to the papal dominions till 1800, when it became part of the kingdom of Italy. It is the birthplace of Lactantius.