[3] On 25 January 2023, Oh joined Scottish Premiership club Celtic for an undisclosed fee, reported to be in the region of £2.5 million, signing a five-year contract.

[7] He made his debut on 29 January 2023, in a league game against Dundee United, replacing Kyogo Furuhashi in the 82nd minute of an eventual 2–0 win.

[9] Oh scored 11 goals during 36 league appearances including six starts, while usually playing as a substitute for main striker Furuhashi.

[4] However, he did not get playing time for half a year after Adam Idah came to the team on a loan deal.

He led Genk's 2–1 win by scoring twice, while playing 31 minutes as a substitute in the next Pro League match against Mechelen on 28 September.