Onamia (pronunciation: /oʊneɪmiːə/ oh-naym-ee-ə) is a city in Mille Lacs County, Minnesota, USA. The population was 878 at the 2010 census. It is the town nearest to Camp Onomia, a Lutheran summer camp.
U.S. Highway 169 and Minnesota Highway 27 are two of the main arterial routes in the community.
According to the United States Census Bureau, the city has a total area of 0.9 square miles (2.3 km²), all of it land.