Lions Clubs International, is an international service organization, currently headquartered in Oak Brook, Illinois, U.S. As of January 2020, it had over 46,000 local clubs and more than 1.4 million members (including the youth wing Leo) in more than 200 countries and geographic areas around the world.

The Association of Lions Clubs was established in 1917 in Chicago, Illinois, by Melvin Jones, a Chicago business leader and a Freemason. The Association went international in 1920 when Border Cities Lions Clubs in Windsor, Canada, was established. The name of Lions Clubs International has been used since then. It subsequently evolved as an international service organization under the guidance and supervision of its secretary, Melvin Jones.

In 1917, Jones was a 38-year-old Chicago business leader who told members of his local business club they should reach beyond business issues and address the betterment of their communities and the world. Jones' group, the Business Circle of Chicago, agreed. After contacting similar groups around the United States, an organizational meeting was held on June 7, 1917, in Chicago. The Business Circle subsequently joined one of the invited groups, the "International Association of Lions Clubs" and at a national convention held in Dallas, Texas, later that year, those who were assembled: (1) adopted a Constitution, By-Laws, Code of Ethics and an Emblem; (2) established as a main tenet "unselfish service to others", (3) unanimously elected Woods as its first president, effectively securing his leadership for the first two years of the existence of the International Association of Lions, and (4) selected Jones to serve as the organization's secretary-treasurer.

The Lions motto is "We Serve". Local Lions Club programs include sight conservation, hearing and speech conservation, diabetes awareness, youth outreach, international relations, environmental issues, and many other programs. The discussion of partisan politics and sectarian religion is forbidden. The LIONS acronym also stands for Liberty, Intelligence, Our Nations' Safety.