Ulsan HD defended their title for the third consecutive year.
[1] FC Anyang were promoted from the 2024 K League 2 for 1st time in club history.
[2] Incheon United was relegated to 2025 K League 2 in the club's first absence from the top flight of Korean football.
[3] The following rules are newly introduced for 2025 season The following twelve clubs are competing in the 2025 K League 1.
[9] As a military-owned team, Gimcheon Sangmu are not allowed to sign any foreign players.