According to the United States Census Bureau, the CDP has a total area of 0.85 square miles (2.2 km2), all land.[5] It is located along North Main Street in Plains Township; it is directly northeast of the CDP of Plains.
North Main Street continues northeastward into Jenkins Township, where it becomes South Main Street and passes through the CDP of Inkerman. The Susquehanna River is less than one-half mile northwest of Hilldale, separating the CDP from the boroughs of Wyoming and Forty Fort.