depends what you mean by largest. soccer would be the largest world wide
The Professional Association of Diving Instructors (PADI) is the largest diver training organization in the world.
National Basketball Association
Utah Jazz is a professional basketball team in the National Basketball Association.
NBA, the National Basketball Association in the United States.
FIFA (Fédération Internationale de Football Association) is the largest sports organization in the world, overseeing international soccer competitions and representing 211 national associations.
The component of sports that tiger woods does (meaning what sport he plays) is golf. He is a professional golfer on the Professional Golf Association and Nationwide tours.
Welsh Sports Association was created in 1972.
Academic Sports Association was created in 1909.
Gary Davidson has written: 'Breaking the game wide open' -- subject(s): American Baseball Association, Professional sports, World Hockey Association
The NFL has way more members(by that you mean players) than any other sport.
The National Education Association (NEA) is both the largest professional organization and labor union in the United States. The NEA supports teachers with services such as, legal issues, labor disputes and professional development.