Longtang is a town in Qiongshan District, Hainan, China. It lies on the west bank of the Nandu River, roughly 15 kilometres south of Haikou, the provincial capital.
Its position along the Nandu River places it within the greater Haikou area, on the island's northern side. The town is one of several settlements in Qiongshan District, the administrative division that also contains the district seat and surrounding communities.