Mount Ayr is a town in Jackson Township, Newton County, in the U.S. state of Indiana.

Mount Ayr was laid out as a town in 1882 when the railroad was extended to that point.

[4][5] The town was named after Mount Airy, North Carolina, the native home of its founder.

[7] According to the 2010 census, Mount Ayr has a total area of 0.15 square miles (0.39 km2), all land.

27.5% of all households were made up of individuals, and 9.8% had someone living alone who was 65 years of age or older.

17.3% of all households were made up of individuals, and 9.6% had someone living alone who was 65 years of age or older.