- James City
- James Creek
- Jamestown
- Jamison
- Jeannette
- Jefferson
- Jenkintown
- Jenners
- Jennerstown
- Jermyn
- Jerome
- Jersey Mills
- Jersey Shore
- Jessup
- Jim Thorpe
- Joffre
- Johnsonburg
- Johnstown
- Jones Mills
- Jonestown
- Josephine
- Julian
- Junedale
- Kane
- Kantner
- Karns City
- Karthaus
- Keisterville
- Kelayres
- Kelton
- Kemblesville
- Kempton
- Kennerdell
- Kennett Square
- Kent
- Kersey
- Kimberton
- Kingsley
- Kingston
- Kintnersville
- Kinzers
- Kirkwood
- Kittanning
- Kleinfeltersville
- Klingerstown
- Knox
- Knox Dale
- Knoxville
- Koppel
- Kossuth
- Kreamer
- Kresgeville
- Kulpmont
- Kulpsville
- Kunkletown
- Kutztown
- Kylertown
- La Belle
- La Jose
- La Plume
- Laceyville
- Lackawaxen
- Lafayette Hill
- Lahaska
- Lairdsville
- Lake Ariel
- Lake City
- Lake Como
- Lake Harmony
- Lake Lynn
- Lake Winola
- Lakeville
- Lakewood
- Lamar
- Lamartine
- Lampeter
- Lancaster
- Landenberg
- Landingville
- Landisburg
- Landisville
- Lanesboro
- Langeloth
- Langhorne
- Lansdale
- Lansdowne
- Lanse
- Lansford
- Laporte
- Larimer
- Latrobe
- Lattimer Mines
- Laughlintown
- Laurelton
- Laurys Station
- Lavelle
- Lawn
- Lawrence
- Lawrenceville
- Lawton
- Le Raysville
- Lebanon
- Leck Kill
- Leckrone
- Lecontes Mills
- Lederach
- Leechburg
- Leeper
- Leesport
- Leetsdale
- Lehigh Valley
- Lehighton
- Lehman
- Leisenring
- Lemasters
- Lemont
- Lemont Furnace
- Lemoyne
- Lenhartsville
- Lenni
- Lenoxville
- Leola
- Levittown
- Lewis Run
- Lewisberry
- Lewisburg
- Lewistown
- Lewisville
- Liberty
- Lickingville
- Lightstreet
- Ligonier
- Lilly
- Limekiln
- Limeport
- Limestone
- Lincoln University
- Linden
- Line Lexington
- Linesville
- Lionville
- Listie
- Lititz
- Little Meadows
- Littlestown
- Liverpool
- Llewellyn
- Lock Haven
- Locust Gap
- Locustdale