Plainfield South High School, or PSHS, is a four-year public high school located in Plainfield, Illinois, a southwest suburb of Chicago, Illinois, in the United States.

The fourth principal of Plainfield South High School was Bob Yanello who served 2015-2023, and the fifth and current principal of Plainfield South High School is Lisa Smith who served since 2023.

A 4000-seat stadium, baseball and softball diamonds, tennis courts, and a track are among outdoor facilities.

The track team has had recent success, winning sixth place in the state finals in 2010.

Plainfield South won the 2022 3A Boys State Cross Country Championship.