Agusan may refer to the following:
In geography
- Agusan province, a former province in the Philippines, now divided between:
- Agusan del Norte
- Agusan del Sur
- Legislative district of Agusan in the Philippines for the former province before it was divided into two separate ones
- Agusan River, a river in Mindanao
- The Agusan Marsh Wildlife Sanctuary
Other
- A symbol in the Tironian notes shorthand system (<span style="font-family: segoe ui symbol, helvetica, dejavu sans, sans-serif"></span>) when used as an abbreviation for agus ("and") in Irish and Scottish Gaelic
- Agusan language, a Manobo language of The Philippines