Nanfaxin is a town in the western part of Shunyi District, Beijing, China. It lies within the municipality of Beijing and forms part of the district's western border area.
The town is bordered by Mapo Town and Shuangfeng Subdistrict to the north, Wangquan Subdistrict and Renhe Town to the east, Capital Airport Subdistrict to the south, and Houshayu and Gaoliying Towns to the west. Its position next to Capital Airport Subdistrict places it near Beijing Capital International Airport.
According to the 2020 Chinese census, Nanfaxin had a population of 54,195 residents.