The 2021 season was Kawasaki Frontale's 17th consecutive season in the J1 League, where they lifted the title for the fourth time in five years.

[1] Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply.

Players may hold more than one non-FIFA nationality.

Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply.

Players may hold more than one non-FIFA nationality.