Paxtonia is an unincorporated community and census-designated place (CDP) in Lower Paxton Township, Dauphin County, Pennsylvania, United States.

Paxtonia is located in the central part of Lower Paxton Township at 40°19′4″N 76°47′28″W / 40.31778°N 76.79111°W / 40.31778; -76.79111 (40.317888, -76.791032).

Interstate 81 forms the northern edge of the CDP, separating it from Linglestown, with access from Exit 72 (Mountain Road).

U.S. Route 22 (Allentown Boulevard) is the main highway through the center of Paxtonia.

According to the United States Census Bureau, the CDP has a total area of 2.3 square miles (6.0 km2), all land.