The CDP is bordered by Caldwell Avenue and Falls Terrace to the northwest, by Vauxhall Avenue and Haines Avenue to the northeast, by Warren Avenue to the east, by the Garden State Parkway to the southeast, by Burke Parkway to the southwest, and by Bond Drie, Rosemont Avenue, Stuyvesant Avenue, and Elmwood Avenue to the south.[7]Connecticut Farms borders the neighborhood to the south.
New Jersey Route 82 (Morris Avenue) is the main street through Union, leading southeast 4 miles (6 km) to Elizabeth and northwest 2 miles (3 km) to Springfield.