The Campionato Sammarinese di Calcio is the top professional football league in San Marino. Established in 1985, it features clubs from the small republic, competing annually for the championship title. The league operates on a promotion and relegation system with the Serie B. Matches are typically held from August to May, with teams playing each other in a round-robin format. The league champion qualifies for the UEFA Champions League, while other teams may enter the UEFA Europa League. The competition is known for its passionate local support despite the small size of the country.