The Ulster Senior League is an association football league featuring amateur, intermediate, and League of Ireland reserve teams. Together with the Leinster Senior League Senior Division and the Munster Senior League Senior Premier Division, it forms the third level of the Republic of Ireland football league system. Ulster Senior League teams also compete in the FAI Cup and the FAI Intermediate Cup. The winners of the Ulster Senior League have also been invited to play in the League of Ireland Cup. Despite using the Ulster name in its title, almost all of its clubs are based in County Donegal and the City of Derry. The most successful club in the league has been Fanad United who have won fourteen league titles and ten league cups. Since 2006 the USL has operated as a summer league with the