- Harmony
- Hat Creek
- Hathaway Pines
- Hawaiian Gardens
- Hawthorne
- Hayfork
- Hayward
- Healdsburg
- Heber
- Helendale
- Helm
- Hemet
- Herald
- Hercules
- Herlong
- Hermosa Beach
- Hesperia
- Hickman
- Hidden Valley Lake
- Highland
- Hilmar
- Hinkley
- Hollister
- Holt
- Holtville
- Holy City
- Homeland
- Homewood
- Honeydew
- Hood
- Hoopa
- Hopland
- Hornbrook
- Hornitos
- Hughson
- Hume
- Huntington Beach
- Huntington Park
- Huron
- Hyampom
- Hydesville
- Idyllwild
- Igo
- Imperial
- Imperial Beach
- Independence
- Indian Wells
- Indio
- Inglewood
- Inverness
- Inyokern
- Ione
- Irvine
- Isleton
- Ivanhoe
- Jackson
- Jacumba
- Jamestown
- Jamul
- Janesville
- Jenner
- Johannesburg
- Jolon
- Joshua Tree
- Julian
- Junction City
- June Lake
- Kaweah
- Keeler
- Keene
- Kelseyville
- Kentfield
- Kenwood
- Kerman
- Kernville
- Kettleman City
- Keyes
- King City
- Kings Beach
- Kingsburg
- Kirkwood
- Kit Carson
- Klamath
- Klamath River
- Kneeland
- Knights Landing
- Knightsen
- Korbel
- Kyburz
- La Canada Flintridge
- La Crescenta
- La Grange
- La Habra
- La Honda
- La Jolla
- La Mesa
- La Mirada
- La Palma
- La Puente
- La Quinta
- La Verne
- Ladera Ranch
- Lafayette
- Laguna Beach
- Laguna Hills
- Laguna Niguel
- Laguna Woods
- Lagunitas
- Lake Arrowhead
- Lake City
- Lake Elsinore
- Lake Forest
- Lake Hughes
- Lake Isabella
- Lakehead
- Lakeport
- Lakeshore
- Lakeside
- Lakewood
- Lamont
- Lancaster
- Landers
- Larkspur
- Lathrop
- Laton
- Lawndale
- Laytonville
- Le Grand
- Lebec
- Lee Vining
- Leggett
- Lemon Cove
- Lemon Grove
- Lemoore
- Lewiston
- Likely
- Lincoln
- Lincoln Acres
- Linden
- Lindsay
- Litchfield
- Little Lake
- Little River
- Littlerock
- Live Oak
- Livermore
- Livingston
- Llano
- Lockeford
- Lockwood