The northern and western ends face the Genkai Sea, and the eastern side borders Fukuoka City.

After the Meiji restoration, the villages of Fukuyoshi, Fukae, Ichikisan, Nagaihon (renamed Nagaito in 1892), Kafuri, Raiyama, Ito, Maehara, Hatae, Kaya, Kofuji, Keya, Nokita, and Sakurai were established on May 1, 1889 with the creation of the modern municipalities system.

Kaya, Sakurano, Kofuji, and Keya merged on January 1, 1955 to form the village of Shima, which became town on April 1, 1965.

Likewise Ichikiyama, Fukae, and merged on January 1, 1955 to form the village of Nijo, which became town on April 1, 1965.

Itoshima has a mayor-council form of government with a directly elected mayor and a unicameral city council of 20 members.

In terms of national politics, the city is part of the Fukuoka 3rd district of the lower house of the Diet of Japan.

JR Kyushu - Chikuhi Line Itoshima is known for its seaside resorts, beaches, and natural beauty.