Alzada is an unincorporated community in Carter County in the southeastern corner of the U.S. state of Montana. It is located at the intersection of U.S. Route 212 with Montana Secondary Highways 323 and 326, near the Wyoming and South Dakota borders. It is in the Mountain Time Zone.
Alzada was first settled as a military telegraph relay station, and was called Stoneville, after the local bartender Lou Stone. It was the site of a famous gun battle in 1884 between local authorities and rustlers known as the Exelby gang. Its name was changed in 1885 because of confusion with another similarly named community. The name Alzada came from an early settler named Laura Alzada Shelden. Later settlers were largely homesteaders. Peter Thompson moved to Alzada from Lead, Dakota Territory, in 1890, with his brother William and homesteaded north of Alzada on the Little Missouri River at Nine Mile Creek.
Alzada was briefly in the news in September 1997 when a B-1 bomber crashed nearby.