John Olof Mellberg (born July 30, 2006) is a Swedish professional footballer who plays as defender for 2.

Liga club FC Liefering, on loan from Red Bull Salzburg.

Mellberg started playing football with the youth academy of IF Brommapojkarna at the age of 9, and was promoted to their senior team for the 2023 season.

On 19 June 2023, he transferred to the Austrian Bundesliga club Red Bull Salzburg on a contract until 2026, and was initially assigned to their partner club FC Liefering.

[2] He made his senior and professional debut with Liefering in a 1–0 loss to Dornbirn on 28 July 2023.