The world's first service club, the Rotary Club of Chicago, Illinois, USA, was formed on 23 February 1905 by Paul P. Harris, an attorney who wished to recapture in a professional club the same friendly spirit he had felt in the small towns of his youth. The name "Rotary" derived from the early practice of rotating meetings among members' offices.

Rotary's popularity spread throughout the United States in the decade that followed; clubs were chartered from San Francisco to New York. By 1921, Rotary clubs had been formed on six continents, and the organization adopted the name Rotary International a year later.

As Rotary grew, its mission expanded beyond serving the professional and social interests of club members. Rotarians began pooling their resources and contributing their talents to help serve communities in need. The organization's dedication to this ideal is best expressed in its principal motto: Service Above Self. Rotary also later embraced a code of ethics, called The 4-Way Test, that has been translated into hundreds of languages.