C. montanus may refer to:
Callistemon montanus, or mountain bottlebrush Cercocarpus montanus, or mountain mahogany Caelostomus montanus, a ground beetle in the subfamily Pterostichinae Chalcides montanus, a skink found in the Atlas Mountains in Morocco Chrysops montanus, a deer fly of the family Tabanidae Cophixalus montanus, a frog species endemic to Indonesia Cybaeus montanus, a spider of the family Cybaeidae