Geneva was an ancient settlement of the Celtic Allobroges, and was later included in Roman Gaul. The bishops of Geneva gradually absorbed the powers of the feudal counts of Geneva and in 1124 became rulers of the city.

The arrival of John Calvin in 1536, thrust upon Geneva a role of European importance as the focal point as its population swelled by Protestant refugees. The city, annexed to France from 1798 to 1813, joined Switzerland as a canton in 1815—the last canton to join the Confederation. Geneva ultimately became a cosmopolitan intellectual center.

Headquarters of many public and private international organizations, in 1864 Geneva was made the seat of the International Red Cross, and is headquarters for the International Labor Organization, the World Health Organization, and other international bodies.

The League of Nations, a world organization established in 1920 to promote international cooperation and peace, was located in Geneva. It was first proposed in 1918 by President Woodrow Wilson, although the United States never joined the League. The League was in effect powerless and it was officially dissolved in 1946.