It has a population of 346,770 (2010) and has a geographic area of 14.22 km2 (5.49 sq mi), and is divided into 14 dong (administrative neighborhoods).

Dongdaemun is located in northeastern Seoul, bordering the city districts of Seongbuk to the northwest, Jongno to the west, Seongdong to the south, Gwangjin to the southeast, and Jungnang to the east.

Yoo Deok-yeol (유덕열) of the Democratic Party has been the mayor of Dongdaemun since July 2010.

Dongdaemun District was first created in 1943 when the "gu" system started and was larger in area than it is today.

The grave sites of Kim Byeongro (김병로 金炳魯), Han Yongwoon (한용운 韓龍雲), Ahn Changho and Oh Sechang (오세창 吳世昌) are also located in this district.