Greycliff is a census-designated place (CDP) in Sweet Grass County, Montana, United States.

Visitors can view the local black-tailed prairie dog community and their mayor, Al Bino, and learn through interactive displays.

[4] According to the United States Census Bureau, the CDP has a total area of 0.3 square miles (0.78 km2), all land.

The Köppen Climate System classifies the weather as humid continental, abbreviated as Dfb.

33.3% of all households were made up of individuals, and 19.0% had someone living alone who was 65 years of age or older.

There were 10.0% of families and 18.8% of the population living below the poverty line, including 16.0% of under eighteens and 33.3% of those over 64.