Oslo is a city in Marshall County, Minnesota, United States. The population was 330 at the 2010 census. Minnesota Highway 1 and Minnesota Highway 220 are two of the main arterial routes in the community. Interstate 29 is nearby. According to the United States Census Bureau, the city has a total area of 0.4 square miles (1.0 km²), of which, 0.4 square miles (0.9 km²) of it is land and 0.04 square miles (0.1 km²) of it (5.26%) is water.