Unionville is an unincorporated community and census-designated place in East Marlborough Township in southern Chester County, Pennsylvania, United States. It was originally known as Jacksonville. The Unionville Village Historic District was added to the National Register of Historic Places in 1979. As of 2020, the CDP has a population of 577.
Unionville is located in the Unionville-Chadds Ford School District.
Unionville High School is a member of the Ches-mont league since 2007, in PIAA District 1.