Suwon Samsung Bluewings Oh made his professional debut in
K League 1 with
Suwon Samsung Bluewings during the
2019 season, making eleven league appearances. He spent the next two seasons on loan at military club Sangju Sangmu (renamed
Gimcheon Sangmu in 2021), where he served his
military service. He returned to the Bluewings in the
2022 season and was the club's top scorer with 13 league goals. He was assigned the number 19 shirt. 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. Then, he scored his first goal for the
Bhoys on 11 February, in a 5–1
Scottish Cup win over
St. Mirren. Oh scored 11 goals during 36 league appearances including six starts, while usually playing as a substitute for main striker Furuhashi.
Genk On 14 July 2024, Oh signed a four-year contract with
Belgian Pro League club
Genk. On 22 September, he scored his first goal for Genk in a 4–0 win over
Dender. On 28 September, 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. He scored 1.33 goals per 90 minutes (9 goals in 610 minutes) as he played as a substitute for main striker
Tolu Arokodare in his first season at Genk. In the summer of 2025, Oh had a medical examination in Germany after receiving an offer from
Bundesliga club
VfB Stuttgart. However, the condition of his
cruciate ligament did not satisfy Stuttgart, and they requested to convert his permanent move into a loan deal. He suffered a cruciate ligament injury in his boyhood, but his knee had no problems during his professional career until this point. Genk refused the request and cancelled his transfer. On 22 August, he scored his first goal at UEFA competitions in the
UEFA Europa League play-off first leg against
Lech Poznań, which ended in a 5–1 win. On 25 September, he scored the winning goal in a 1–0 win over
Rangers, the first
league phase match at the Europa League. He played as a main striker for Genk during the first half of the 2025–26 season, but his status at the club was lowered again after manager
Thorsten Fink was sacked for poor results until December.
Beşiktaş in 2026 On 4 February 2026, Oh signed a three-and-a-half-year contract with
Süper Lig club
Beşiktaş, who paid a transfer fee of €14 million. On 8 February, he scored an equaliser and won a penalty in his first Süper Lig match against
Alanyaspor, which ended in a 2–2 draw. He also scored a goal in each of the two subsequent matches against
İstanbul Başakşehir and
Göztepe, becoming the first-ever Beşiktaş player to score in all of the first three matches. ==International career==