The 2026 League of Ireland First Division, known as the SSE Airtricity Men's First Division for sponsorship reasons, is the 42nd season of the League of Ireland First Division for men's football. The competition is scheduled to run from 13 February 2026 and until 16 October 2026.
The 2025 League of Ireland First Division, saw Dundalk promoted after one season in the First Division. They replaced Cork City who were relegated from the 2025 League of Ireland Premier Division after a single season in the Premier Division.
<small>Note: Flags indicate national team as has been defined under FIFA eligibility rules. Players may hold more than one non-FIFA nationality.</small>
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Teams play each other four times (twice at home and twice away).