The Asociación de Clubs de Baloncesto (ACB) (), commonly known as the Liga ACB, is the pre-eminent men's professional basketball league in Spain. It was founded in 1956 with the name of Liga Nacional. The league changed its name to the current one in 1983. The league is rated as one of the three "A" level European national domestic leagues in the ULEB League Rankings system. The ACB League is considered by many to be one of the best and most elite basketball leagues in Europe and even in the whole world.