I
- Ibis
- Idria
- Idyllwild
- Idylwood
- Ignacio
- Igo
- Ilmon
- Imola
- Imperial
- Imperial Beach
- Inca
- Incline
- Independence
- Indian Creek
- Indian Falls
- Indian Gulch
- Indian Lakes Estates
- Indian Oaks
- Indianola
- Indian Rock
- Indian Springs
- Indian Springs
- Indian Springs
- Indian Springs
- Indian Village
- Indian Wells
- Indian Wells
- Indio
- Industry
- Ingle
- Inglewood
- Ingomar
- Ingot
- Ingram
- Inperial Gables
- Inskip
- Interlaken
- Inverness
- Inwood
- Inyokern
- Ione
- Iowa City
- Iowa Hill
- Iris
- Irish Town
- Irmulco
- Iron Horse
- Iron Mountain
- Irrigosa
- Irvine
- Irvington District
- Irwin
- Irwindale
- Irwin Estates
- Island Mountain
- Isla Vista
- Isleton
- Italian Ranch
- Italian Swiss Colony
- Ivanhoe
- Ivanpah
- Iverson Indian Rancheria
- Ivesta