Gabriel Gemayel studied pharmacy at St. Joseph University in Beirut, where he captained the university football team to three championships from 1925-1927. He held several important roles in sporting administration, most notably the presidency of the Lebanese Football Federation from 1942-1943 and in the 1950s. In 1947 he founded the Lebanese Olympic Committee, serving as President until his death in 1988. He became an IOC Member in 1952, and served on the Executive Board from 1965-69. He later served on IOC Commissions, notably the Solidarity Commission. In 1957 he helped organize the Arab Games and he was on the Organizing Committee of the 1959 Mediterranean Games in Beirut. His brother Pierre was an influential Lebanese politician, and two of his nephews, Bachir and Amine, served as President of Lebanon.