Liga 1, formerly known as Indonesian Super League, is the top professional football competition in Indonesia. Liga 1 is contested by 18 teams, with three lowest teams relegated to Liga 2. It is officially known as GO-JEK Liga 1 for sponsorship reasons.
Liga 1 is operated by PT. Liga Indonesia Baru, with 18 clubs act as shareholders. Seasons usually run for a year from March to December. Teams play 34 matches each (home and away).
PSSI restricting the number of foreign players strictly to four per team, including a slot for a player from AFC countries and one marquee player starting 2017 season. A team could use four foreign players on the field each game including a least one player from the AFC confederation.