Cẩm Khê is a mountainous district in western Phú Thọ province, Vietnam. The district borders Hạ Hòa district to the north, Tam Nông district to the south, Yên Lập district to the west, and Thanh Ba district to the east. It covers an area of 234.2 square kilometres. According to 2002 census figures, the district has a population of 128,537 and a workforce of 65,720.