Cajatambo is one of nine provinces in the Lima Region of Peru.

It is bordered to the north by the Ancash Region, to the east by the Huánuco Region, to the south by the province of Oyón, and to the west by the province of Huaura.

The Waywash mountain range traverses the province.

Historically, the principal products of the province have been cattle and sheep, although cochineal is also produced in the area.

This Lima Region geography article is a stub.