Big Sandy Creek (Gros Ventre: báasnɔ́ɔ́ɔ́béʔ, lit.

'big sand'[2]) is a tributary of the Milk River, approximately 50 miles (80 kilometers) long, in northwestern Montana in the United States.

It rises in the southern Rocky Boys Indian Reservation in the Bears Paw Mountains and flows southwest, then north past Box Elder, then northeast, joined by Sage Creek, and joins the Milk approximately 10 mi (16 km) west of Havre.

Big Sandy Creek has also been known as: Ahmi-Saptsiko, Sand Creek, and Un-es-putcha-eka.

This article related to a river in Montana is a stub.