Dadeng Island is an island in the southeastern part of Xiang'an District, Xiamen City, Fujian Province, People's Republic of China, with an area of approximately 13 square kilometers. Administratively, it is currently under the jurisdiction of Dadeng Subdistrict in the same district. There is a Dadeng Militia outpost on the island, established in 1950 and initially manned by local residents. Since 1992, it has been manned by a fixed rotation of 10 local female militia members.