- Ibis
- Iceland
- Ida Island
- Ideal Mobile Home Park
- Idlewild
- Idlewild
- Idlewild
- Idria
- Idyllwild
- Idyllwild-Pine Cove
- Igerna
- Ignacio
- Igo
- Ilmon
- Imhoff
- Imperial
- Imperial Beach
- Inca
- Incline
- Independence
- Independence, Rail Rd Flat
- Indian Creek
- Indian Creek Trailer Park
- Indian Falls
- Indian Gulch
- Indian Hills
- Indian Island
- Indian Island
- Indian Island
- Indian Lakes Estates