Iki Province (壱岐国 Iki no kuni?) was a province of Japan which consisted of the Iki Islands, now a part of modern Nagasaki Prefecture. Its abbreviated name was Isshū (壱州?). Iki is classified as one of the provinces of the Saikaidō. Under the Engishiki classification system, Iki was ranked as a “inferior country” (下国) and a "far country" (遠国).
The Iki Islands have been inhabited since the Japanese Paleolithic era, and numerous artifacts from the Jomon, Yayoi and Kofun periods have been found by archaeologists, indicating continuous human occupation and activity. In the Chinese Weizhi Worenchuan (Japanese 魏志倭人伝, Gishi Wajinden), part of the Records of the Three Kingdoms dating from the 3rd century AD, mention is made of a country called “Ikikoku”, (一支国), located on an archipelago east of the Korean Peninsula. Archaeologists have tenatively identified this with the large Yayoi period settlement of Harunotsuji (原の辻), one of the largest to have been discovered in Japan, where artifacts uncovered indicate a close contact with the Japanese islands and the Asian mainland. It is also mentioned in the Weilüe, the Book of Liang and the Book of Sui.