| Official Name: | Onamia Township, Minnesota |
| Settlement Type: | Township |
| Pushpin Map: | Minnesota#USA |
| Pushpin Label Position: | left |
| Pushpin Map Caption: | Location within the state of Minnesota |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Minnesota |
| Subdivision Type2: | County |
| Subdivision Name2: | Mille Lacs |
| Unit Pref: | Imperial |
| Area Total Km2: | 93.6 |
| Area Land Km2: | 92.5 |
| Area Water Km2: | 1.1 |
| Population As Of: | 2010 |
| Population Total: | 575 |
| Population Density Km2: | auto |
| Timezone: | Central (CST) |
| Utc Offset: | -6 |
| Timezone Dst: | CDT |
| Utc Offset Dst: | -5 |
| Elevation M: | 386 |
| Elevation Ft: | 1266 |
| Coordinates: | 46.0181°N -93.6417°W |
| Postal Code Type: | ZIP code |
| Postal Code: | 56359 |
| Area Code: | 320 |
| Blank Name: | FIPS code |
| Blank Info: | 27-48328[1] |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 0665210[2] |
Onamia Township is a township in Mille Lacs County, Minnesota, United States. The population was 575 at the 2010 census.[3]
According to the United States Census Bureau, the township has a total area of 93.6sqkm, of which 92.5sqkm is land and 1.1sqkm, or 1.13%, is water.[4]
As of the census of 2000, there were 583 people, 218 households, and 163 families residing in the township. The population density was 16.2 people per square mile (6.3/km). There were 258 housing units at an average density of 7.2/sq mi (2.8/km). The racial makeup of the township was 96.05% White, 2.57% Native American, 0.34% from other races, and 1.03% from two or more races. Hispanic or Latino of any race were 1.20% of the population.
There were 218 households, out of which 35.8% had children under the age of 18 living with them, 61.5% were married couples living together, 10.6% had a female householder with no husband present, and 24.8% were non-families. 18.8% of all households were made up of individuals, and 7.3% had someone living alone who was 65 years of age or older. The average household size was 2.67 and the average family size was 3.02.
In the township the population was spread out, with 27.6% under the age of 18, 8.1% from 18 to 24, 29.8% from 25 to 44, 21.8% from 45 to 64, and 12.7% who were 65 years of age or older. The median age was 38 years. For every 100 females, there were 112.0 males. For every 100 females age 18 and over, there were 103.9 males.
The median income for a household in the township was $33,889, and the median income for a family was $41,786. Males had a median income of $26,458 versus $19,318 for females. The per capita income for the township was $15,735. About 10.5% of families and 14.4% of the population were below the poverty line, including 19.8% of those under age 18 and 3.2% of those age 65 or over.