Naranjo is a canton in the Alajuela province of Costa Rica. The head city is located in the homonymous Naranjo district.
It is named for the citrus plantations found in the area. In Spanish a refers to an orange tree, while the fruits are .
Naranjo was created on 9 March 1886 by decree 9.
Naranjo has an area of km<sup>2</sup> and a mean elevation of 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.
The canton of Naranjo is subdivided into the following districts:
For the 2011 census, Naranjo had a population of inhabitants.
The canton is covered by the following road routes: