Port William is a village in Clinton County, Ohio, United States.

Port William was originally called West Liberty, and under the latter name was platted in 1832.

[5] According to the United States Census Bureau, the village has a total area of 0.12 square miles (0.31 km2), all land.

The racial makeup of the village was 95.74% White, 3.49% Native American, and 0.78% from two or more races.

19.6% of all households were made up of individuals, and 8.2% had someone living alone who was 65 years of age or older.

About 10.1% of families and 16.0% of the population were below the poverty line, including 26.8% of those under the age of eighteen and 23.8% of those 65 or over.