The 2019 Oita Trinita season involves the team competing in the J1 League after being promoted by finishing 2nd in the 2018 J2 League.

[2] They will also compete in the J.League Cup and the Emperor's Cup.

As of 2 March 2019.

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

Players may hold more than one non-FIFA nationality.