was a province of Japan in the area of northwestern Shikoku. Iyo bordered on Sanuki Province to the northeast, Awa to the east, and Tosa to the south. Its abbreviated form name was . In terms of the Gokishichidà  system, Iyo was one of the provinces of the Nankaidà  circuit. Under the Engishiki classification system, Iyo was ranked as one of the "upper countries" (ä¸Âå½) in terms of importance, and one of the "far countries" (é å½) in terms of distance from the capital. The provincial capital was located in what is now the city of Imabari, but its exact location is still unknown. The ichinomiya of the province is the à Âyamazumi Shrine located on the island of à Âmishima in what is now part of Imabari. The people spoke Iyo dialect.
Iyo Province was formed by the Ritsuryo reforms by combining the territories of the , who ruled a territory centered on what is now the city of Iyo and town of Masaki with Kumi Province, Kazehaya Province, Touma Province, and Koichi Province each ruled by its own kuni no miyatsuko. The Geiyo Islands in the Seto Inland Sea were considered part of Aki Province into the Edo Period. During the Heian period, the coastal areas of the province were part of the stronghold of Fujiwara no Sumitomo, who led a rebellion against Imperial authority. During the Muromachi period, a branch of the Saionji family was appointed as shugo by the Ashikaga shogunate, but was constantly being invaded his more powerful and aggressive neighbors. The Saionji survived by the fluid loyalties and fierce resistance, but were eventually overcome by Chà Âsokabe Motochika, who was in turn overthrown by the forces of Toyotomi Hideyoshi. Under the Tokugawa shogunate, the province was divided into several feudal domains.
Per the early Meiji period , an official government assessment of the nationâÂÂs resources, the province had 964 villages with a total kokudaka of 434,408 koku. Iyo Province consisted of the following districts:
Following the abolition of the han system in 1871, Iyo Province became Ehime Prefecture.