| Official Name: | Waltham 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: | Mower |
| Unit Pref: | Imperial |
| Area Total Km2: | 93.0 |
| Area Land Km2: | 93.0 |
| Area Water Km2: | 0.0 |
| Area Total Sq Mi: | 35.9 |
| Area Land Sq Mi: | 35.9 |
| Area Water Sq Mi: | 0.0 |
| Population As Of: | 2000 |
| Population Total: | 416 |
| Population Density Km2: | 4.5 |
| Population Density Sq Mi: | 11.6 |
| Timezone: | Central (CST) |
| Utc Offset: | -6 |
| Timezone Dst: | CDT |
| Utc Offset Dst: | -5 |
| Elevation M: | 393 |
| Elevation Ft: | 1289 |
| Coordinates: | 43.7958°N -92.8797°W |
| Postal Code Type: | ZIP code |
| Postal Code: | 55982 |
| Area Code: | 507 |
| Blank Name: | FIPS code |
| Blank Info: | 27-67936[1] |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 0665907[2] |
Waltham Township is a township in Mower County, Minnesota, United States. The population was 416 at the 2000 census. The largest town in the township is Waltham with a population of 196 people. All other area in the township is unincorporated.
Nels Johnson, the earliest settler, came in the summer of 1855. The entire township was later sold to land speculators. John C. Mason bought more than a quarter of the township, primarily in the northeast corner. His agent, A.J. Burbank, came in 1864, built a three-story hotel, surveyed the land and sold most of it off into small parcels. The township was officially organized in 1866.[3] The village of Waltham was originally about a mile east of where it sits now. The Chicago Great Western Railway stretched across the prairie of Waltham Township and the people of the village decided to relocate. The current village of Waltham was platted in 1885. In 1911 the village had two general stores, a physician, a shoe shop, a livery, a creamery, a stock buyer, a carpenter shop, a flour mill, and a variety of small shops.
According to the United States Census Bureau, the township has a total area of 35.9 square miles (93.0 km), all land.
As of the census of 2000, there were 416 people, 146 households, and 117 families residing in the township. The population density was 11.6 people per square mile (4.5/km). There were 150 housing units at an average density of 4.2/sq mi (1.6/km). The racial makeup of the township was 98.56% White, 0.48% Asian, 0.96% from other races. Hispanic or Latino of any race were 1.20% of the population.
There were 146 households, out of which 35.6% had children under the age of 18 living with them, 68.5% were married couples living together, 4.1% had a female householder with no husband present, and 19.2% were non-families. 13.0% of all households were made up of individuals, and 8.2% had someone living alone who was 65 years of age or older. The average household size was 2.85 and the average family size was 3.15.
In the township the population was spread out, with 27.6% under the age of 18, 7.5% from 18 to 24, 26.7% from 25 to 44, 22.8% from 45 to 64, and 15.4% who were 65 years of age or older. The median age was 39 years. For every 100 females, there were 108.0 males. For every 100 females age 18 and over, there were 118.1 males.
The median income for a household in the township was $47,500, and the median income for a family was $49,643. Males had a median income of $28,611 versus $23,889 for females. The per capita income for the township was $16,228. About 4.2% of families and 6.0% of the population were below the poverty line, including 4.3% of those under age 18 and 8.3% of those age 65 or over.
Mayville is an unincorporated community on the southern border with Red Rock Township. It is located along Mower County Highway 16.