Cotter is a city in western Louisa County, Iowa, United States.

It was located along the Chicago, Rock Island and Pacific Railroad.

[5] According to the United States Census Bureau, the city has a total area of 0.25 square miles (0.65 km2), all land.

There were 18 housing units at an average density of 183.8 per square mile (71.0/km2).

At the 2010 census there were 48 people in 19 households, including 14 families, in the city.

There were 24 housing units at an average density of 96.0 per square mile (37.1/km2).

There were 19 housing units at an average density of 81.2 per square mile (31.4/km2).

The racial makup of the city was 85.42% White, 4.17% African American, 10.42% from other races.

There were 11.1% of families and 18.9% of the population living below the poverty line, including 37.5% of under eighteens and none of those over 64.