Ballantine is a census-designated place (CDP) in Yellowstone County, Montana, United States. It lies about 9 miles (10 km) northeast of Billings on Interstate 94. The population was 346 at the 2000 census. Ballantine, along with the communities of Pompey's Pillar, Worden, and Huntley, is part of the Huntley Project, an irrigation district created by the United States Bureau of Reclamation.