Ningcheng County (Mongolian: ᠨᠢᠩᠴᠧᠩ ᠰᠢᠶᠠᠨ Niŋčėŋ siyan; simplified Chinese: 宁城县; traditional Chinese: 寧城縣; pinyin: Níngchéng Xiàn) is a county of southeastern Inner Mongolia, People's Republic of China, bordering Liaoning province to the east. It is under the administration of Chifeng City.It was formerly known as Beijing under the 12th-century Jurchen Jin dynasty, who used it as their northern capital.