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

Rotary's popularity spread, and within a decade, clubs were chartered from San Francisco to New York to Winnipeg, Canada. By 1921, Rotary clubs had been formed on six continents. The organization adopted the Rotary International name a year later.

In 1989, the organization voted to admit women into clubs worldwide and now claims more than 145,000 female members in its ranks.

Today, 1.2 million Rotarians belong to over 32,000 Rotary clubs in more than 200 countries and geographical areas.