Naranjo is a canton in the Alajuela province of Costa Rica. The head city is located in the homonymous Naranjo district.
Naranjo has an area of 126.62 km2 and a mean elevation of 1,121 metres.
The Grande River forms the western and southern boundaries of the canton. The Espino River is on the north, and the Colorado and Molino rivers establish the eastern border.