Buffalo is an unincorporated rural hamlet in Fergus County, Montana, United States. Buffalo has a church, a post office serving ZIP code 59418, no other businesses or services, and only perhaps half a dozen homes. It was named for the buffalo which roamed this area. The post office was established in 1890. It closed for several years until the Great Northern Railroad created a line to Billings with Buffalo as a station. Buffalo is bordered by Lewis and Clark National Forest.