Pleasant Plain is a city in northeast Penn Township, Jefferson County, Iowa, United States.

[4] According to the United States Census Bureau, the city has a total area of 1.02 square miles (2.64 km2), all land.

There were 42 housing units at an average density of 41.5 per square mile (16.0/km2).

There were 47 housing units at an average density of 46.1 per square mile (17.8/km2).

24.4% of all households were made up of individuals, and 19.5% had someone living alone who was 65 years of age or older.

There were 57 housing units at an average density of 56.2 per square mile (21.7/km2).

19.2% of all households were made up of individuals, and 7.7% had someone living alone who was 65 years of age or older.

There were 24.3% of families and 25.0% of the population living below the poverty line, including 50.0% of under eighteens and 20.0% of those over 64.