Iyo (Japanese: 伊予市) is a city on the central coast of Ehime Prefecture, on the island of Shikoku in Japan. It covers 194 sq km (75 sq mi) and has a population of 40,000 people (2012 estimate).
Human habitation in the Iyo area can be traced to the Yayoi period (300 BC to 250 AD). However the present city is more recent, with its beginnings traced to 1635. It was first made a city in 1955, when the town of Gunchu merged with the villages of Kitayamasaki and Minamiyamasaki. In 2005, the city increased its limits when it merged with the towns of Nakayama and Futami to create the present city of Iyo.
Iyo produces mostly food products such as Bonito flakes, mikan, Nakayama chestnuts and fruits.