Elkhorn is a census-designated place (CDP) in Jefferson County, Montana, United States, in the Elkhorn Mountains of the southwestern part of the state. As of the 2010 census it had a population of 10. The community is considered of a ghost town, and two of its buildings are preserved as Elkhorn State Park.

Lodes of silver, described by geologists as supergene enrichments, were initially discovered in the Elkhorn Mountains by Peter Wys, a Swiss immigrant. Six years later, Anton Holter, a pioneer capitalist from Helena, began developing the mine. Over $14 million in silver was carried from the mine. In 1890, the Sherman Silver Purchase Act passed, creating a high demand for Elkhorn's silver.

During this peak period, Elkhorn had 2,500 inhabitants, a school, a hotel, a church, stores, saloons, and brothels. Unlike most mining towns, Elkhorn was populated mostly by families of married European immigrants. In 1893, the Fraternity Hall was constructed for social gatherings, and still remains as one of the most well-preserved buildings in modern Elkhorn.