ROK Marine Corps to Regain Operational Control of Its Units from the Army
I did not realize that the ROK Marine Corps fell under the control of the ROK Army. Well that is about to soon change:

Defense Minister Ahn Gyu-back gives a red name tag to a conscript at the Marine Corps Education and Training Group in the southeastern port city of Pohang on Dec. 26, 2025, in this photo provided by his office. (Yonhap)
The operational control of two Marine divisions, now governed by the Army, will be restored to the Marine Corps for the first time in 50 years as part of a military overhaul, the defense ministry said Wednesday.
The move is designed to ensure the independence of the Marine Corps by fully restoring its operational control over its military units.
Under the plan, the operational control of the 1st Marine Division and the 2nd Marine Division will be returned to the Marine Corps by the end of 2026 and 2028, respectively.
The operation control of the 1st Marine Division currently lies with the Army’s commander of the 2nd Operation Command, while that of the 2nd Marine Division is subject to control of the Army’s Capital Corps.
You can read more at the link.


Why were they separated from the Navy? The wiki page is a bit unclear.
https://en.wikipedia.org/wiki/Republic_of_Korea_Marine_Corps