Namyangju is a city in Gyeonggi Province, South Korea. To the east is Gapyeong County, to the west is Guri City, and to the north is Pocheon City. Namyangju-si was originally a southern part of Yangju-gun, but was separated into Namyangju-gun in April 1980. In 1995, Migeum-si and Namyangju-gun were merged to form an urban and rural complex. The city hall is located in Geumgok-dong and Dasan-dong, and the administrative districts are 6-eup, 3-myeon, and 7-dong.

Gyeonggi Province is the most populous province in South Korea.