[1] On 7 February 2022, he signed his first semi-professional contract with the club ahead of the 2022 K League 1 season.
[3] He made 19 appearances in his debut season with Seongnam, earning interest from clubs abroad.
[7] On 7 June 2024, Kim was officially promoted to the senior team,[8] becoming the first-ever Korean centre-back to be affiliated to a Premier League club.
[9] He made his Premier League debut on December 27, coming on as a 76th minute substitute for Ben Mee in a match against Brighton & Hove Albion.
[11] In August 2023, Kim received his first call-up to the South Korea senior national team by head coach Jürgen Klinsmann, for two friendly matches against Wales and Saudi Arabia.