Cangwu is a county in the eastern part of the Guangxi Zhuang Autonomous Region in southern China. It lies under the administration of Wuzhou, a prefecture-level city, and forms part of Guangxi's border with Guangdong province to the east and south.
The county's position on the eastern edge of Guangxi places it within a region of southern China where the Guangxi and Guangdong cultural and economic spheres meet. Its administrative seat and surrounding settlements are located in the hilly terrain typical of this part of the province.
Cangwu is known as a producer of Liubao Tea, a type of dark tea associated with the Wuzhou area of Guangxi. The tea is one of the county's notable local products.