Clarendon is a borough in Warren County, Pennsylvania, United States.

[3] According to the United States Census Bureau, the borough has a total area of 0.4 square miles (1.0 km2), all land.

There were 239 housing units at an average density of 554.5 per square mile (214.1/km2).

The racial makeup of the borough was 97.52% White, 0.18% Native American, 1.06% Asian, and 1.24% from two or more races.

26.8% of all households were made up of individuals, and 15.5% had someone living alone who was 65 years of age or older.