McMillan Township is a civil township of northern Luce County in the U.S. state of Michigan. The population was 3,947 at the 2000 census. Most of the township's population lives in the village of Newberry, the county seat, at the township's extreme south.
There were 1,240 households out of which 30.7% had children under the age of 18 living with them, 50.9% were married couples living together, 10.6% had a female householder with no husband present, and 34.4% were non-families. 30.8% of all households were made up of individuals and 15.3% had someone living alone who was 65 years of age or older. The average household size was 2.35 and the average family size was 2.89.
In the township the population was spread out with 19.7% under the age of 18, 10.8% from 18 to 24, 34.9% from 25 to 44, 20.1% from 45 to 64, and 14.5% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 146.2 males. For every 100 females age 18 and over, there were 165.0 males.
The median income for a household in the township was $30,514, and the median income for a family was $35,101. Males had a median income of $30,118 versus $20,608 for females. The per capita income for the township was $17,007. About 14.6% of families and 16.9% of the population were below the poverty line, including 19.8% of those under age 18 and 9.7% of those age 65 or over.