Dangsan-dong is a legal district that holds the administrative districts of Dangsan 1·2-dong, consisting of two administrative districts. Historically, the region was abundant with azalea trees that bloomed profusely in late spring, leading to the name Dangsan-dong. Another explanation for the name is the presence of the mountain known as 'Dansan' (單山) at Dangsan-dong 110, where a military camp once held 'Dangje' (堂祭) ceremonies.
Initially under the jurisdiction of Gyeongseong-bu on April 1, 1936, overseeing Dangsan, Yangpyeong, and Yanghwajeonghoe, Dangsan 1-dong separated from Yangpyeong and Yanghwajeong in 1941. Subsequently, in March 1948, Dangsan 1-dong and Jungdong 2-dong were divided into three districts, and in April 1955, they were further subdivided into Dangsan 1~4-dong during the neighborhood system implementation.