The municipality has about 500 inhabitants and is located in the lower Ufita valley, near the Calore river and borders the municipality of Buonalbergo in the northern part.
Before 1862, Sant’Arcangelo Trimonte was known as Montemalo. Later, King Victor Emmanuel II renamed it Sant’Arcangelo, to which Trimonte was then added in 1864 to distinguish it from other existing Italian towns of the same name.
The first certain information dates back to the second half of the 12th century, when the land was owned by a certain Guglielmo Fontanarosa.
Later, the territory became the property of the Caracciolo, Guevara and Coscia families, who remained in possession until the feudal system was abandoned. Subsequently, the municipality became part of Principato Ultra until 1861. After the Unification of Italy, Sant’Arcangelo Trimonte was integrated into the province of Avellino and finally united with the province of Benevento in 1978.