Clancy is an unincorporated community and census-designated place (CDP) in Jefferson County, Montana, United States.

The town was founded in 1873 as a gold camp and named for prospector William Clancey.

According to the United States Census Bureau, the CDP has a total area of 39.2 square miles (101.4 km2), all land.

[3] The CDP includes the community of Alhambra, 1 mile (1.6 km) south of Clancy proper.

[5] Most people who live in and around Clancy work in Montana's capital city of Helena, which is a short drive north on I-15.

Elkhorn Health and Rehabilitation runs a small nursing home in the community, and Clancy Elementary School, a K-8 institution, employs more than thirty people.

[10] Jefferson High School in Boulder serves the Clancy students.