Pleasant Plain is a village in Harlan Township, Warren County, Ohio, United States.

[5] According to the United States Census Bureau, the village has a total area of 0.16 square miles (0.41 km2), all land.

The racial makeup of the village was 97.4% White, 1.9% African American, and 0.6% from two or more races.

20.7% of all households were made up of individuals living alone, in addition with 5.1% who were 65 years of age or older.

20.0% of all households were made up of individuals living alone, in addition with 5.5% who were 65 years of age or older.

About 4.2% of families and 7.3% of the population were below the poverty line, including 14.6% of those under the age of eighteen and 11.1% of those 65 or over.