Martin City is an unincorporated community and census-designated place (CDP) in Flathead County, Montana, United States. As of the 2010 census, it had a population of 500, up from 331 in 2000.
Martin City is located in central Flathead County at 48°23′26″N 114°2′7″W (48.390443, -114.035250), between Hungry Horse to the southwest and Coram to the north. U.S. Route 2 passes through the community, leading northeast 9 miles (14 km) to West Glacier and southwest 24 miles (39 km) to Kalispell.
According to the United States Census Bureau, the CDP has a total area of 1.7 square miles (4.5 km2), of which 0.02 square miles (0.05 km2), or 1.16%, is water. Martin City is located on the east side of the Flathead River.
As of the census of 2000, there were 331 people, 142 households, and 94 families residing in the CDP. The population density was 696.2 people per square mile (266.2/km2). There were 163 housing units at an average density of 342.8 per square mile (131.1/km2). The racial makeup of the CDP was 88.52% White, 8.46% Native American, 0.30% from other races, and 2.72% from two or more races. Hispanic or Latino of any race were 0.60% of the population.