The 5th Infantry Division (Korean: 제5보병사단; Hanja: 第五步兵師團), also known as The Key Division (열쇠부대) is a unit of the Republic of Korea Army.

It is a frontline division that protects the GOP and GP of Yeoncheon County, Gyeonggi Province.

The division was created on 29 April 1948, participated the Korean War and it is one of the first units of the South Korean Army.