It is part of the State College, Pennsylvania Metropolitan Statistical Area.

The population was 1,196 at the time of the 2020 census, a decline from the figure of 1,224 tabulated in 2010.

[2][3] Part of Bald Eagle State Park is in Marion Township.

According to the United States Census Bureau, the township has a total area of 22.0 square miles (57.1 km2), all land.

13.0% of all households were made up of individuals, and 5.3% had someone living alone who was sixty-five years of age or older.