Iijima (飯島町, Iijima-machi) is a town located in Nagano Prefecture, Japan.

The total area of the town is 86.96 square kilometres (33.58 sq mi).

The area of present-day Iijima was part of ancient Shinano Province, and developed as a post station in the Sanshū Kaidō highway linking inland regions of Shinano with the Pacific Ocean.

The area was tenryō territory controlled directly by the Tokugawa shogunate until the Meiji restoration.

Per Japanese census data,[4] the population of Iijima has remained relatively steady from 1960 until 2000 but has decreased slightly in recent years.