Baiano is a commune, population 4,743, in the Province of Avellino in the Italian region Campania, located in the Agro Nolano.

[3] It borders the communes of Avella, Mugnano del Cardinale, Sirignano, Sperone and Visciano.

It was later part of the Lombard duchy of Benevento and the Norman principality of Salerno and is recorded in 1129 as a casale of Avella, while in 1210 it was taxed separately.

In 1715 it became an autonomous municipality with the name of Bajano (a name it kept until the early 20th century) and was formerly part of the province of Terra di Lavoro, mandamento di Bajano (of which Avella, Mugnano del Cardinale, Quadrelle, Sirignano and Sperone were also part).

Until 1923 (the date of the abolition of the mandamento as an administrative subdivision) it was chief town of the mandamento of the same name and was the seat of the magistrate's court, the mandala prison and other administrative offices.