League of Ireland

The League of Ireland is a national association football league consisting of professional clubs in the Republic of Ireland and Derry City F.C. in Northern Ireland. It is governed by the Football Association of Ireland. It was the name of the single division top-level football league in the Republic of Ireland from its foundation in 1921 until the introduction of a second division in 1985, upon which it became the name of the league in its entirety.

There are three divisions in the league as of the end of the 2025 season – the Premier Division and First Division for men, and the Women's Premier Division. From 2026, a third tier for men, the National League is anticipated to begin play.

The men's league is divided into the Premier Division and the First Division with ten teams in each division, and promotion and relegation between the highest-placed teams in the First Division and the lowest-placed teams in the Premier Division. From 2026, the National League will consist of a further twenty teams in two parallel conferences of ten teams, North and South. Underage divisions include the U19 Division, U17 Division, U15 Division, and most recently the U14 Division.

Of the twenty teams currently in the Premier Division and First Division, nineteen teams are located in the Republic of Ireland, while one – Derry City – is located in Northern Ireland. League teams also participated in two knockout cup competitions: the FAI Cup, organised by the FAI, and until its suspension in 2020, the League of Ireland Cup.

The league has always worked closely with the FAI, with which it formally merged in 2006. The league is currently sponsored by SSE Airtricity, and as such is known as the SSE Airtricity League for sponsorship reasons. In 2007, it became one of the first leagues in Europe to introduce a salary cap.