Viking is a city in Marshall County, Minnesota, United States. The population was 79 at the 2020 census. A post office called Viking ha…Viking is a city in Marshall County, Minnesota, United States. The population was 79 at the 2020 census. A post office called Viking has been in operation since 1890. The city was organized in 1884, and was named by Rev. Hans P. Hansen, a Norwegian Lutheran pastor in Warren, after the Vikings.