Leo Clubs are an extension of the Lions service organization which aims to encourage community service and involvement from a young age. Much like Lioness Clubs, Leo Clubs are sponsored by a parent Lions Club. Leo Clubs are required to have a Leo Club Advisor, a member of the sponsoring Lions Club who attends meetings and provides general advice to the Club. Lions International includes more than 250,000 Leo Club members in over 150 countries.

Leo Clubs can be identified in 2 different ways according to their membership:

• Alpha Leo Clubs - Leo Clubs with members between the ages of 12 and 18 are commonly referred to as Alpha Leo Clubs. This will usually include school-based Leo Clubs as well as some community-based Leo Clubs.

• Omega Leo Clubs - Leo Clubs with members between the ages of 18 and 30 are commonly referred to as Omega Leo Clubs. This will usually include university-based Leo Clubs as well as most community-based Leo Clubs.

American businessman Melvin Jones (1879–1961) established Lions Clubs International, which celebrated its 100th anniversary in June 2017. His leadership provided the Lions Clubs the reputation they needed to draw prospective members from service-minded businesses, and his objective was to get business involved in community initiatives. To create such a group, Jones invited men's club delegates to Chicago, Illinois, in the United States where on June 7, 1917, the Lions Clubs International (LCI) headquarters were created.

The Lions Clubs International Foundation was established in 1968 with the purpose of "supporting Lions Clubs and partners to serve communities both locally and globally, providing hope and impacting lives via humanitarian service initiatives and grants." The Leo Club Program Department and Leo Club Program Advisory Panel are both affiliated with Lions Club International where Leo Clubs are administered by the Leo Club Program Department, which also acts as its headquarters.

The Lions Clubs International has segregated the world into 7 administrative regions called Constitutional Areas where both Sri Lanka and Maldives fall under the Multiple District 306.

Leo-Lionism is a concept introduced by the Lions Clubs International which provides Leos the opportunity for a smooth transitioning period from a Leo to a Lion where the Leos are provided with the exposure to Lionism and its benefits from a young age up until 36 years of age. The Leos can either join a Leo-Lions Club or a Lions Club in order to continue their journey as a Leo Lion.

Leos are provided with benefits by joining Leo-Lionism such as 50% discount on the dues paid to the Lions Clubs International, no entrance fees when joining a Lions Club, eligibility to apply for Lions cabinet positions in the Lions District, gain similar recognitions as Lions and the ability to apply for Lions Leadership Institute scholarships.