- Ideal
- Idlewild
- Idlewood
- Idylside
- Iles
- Illiana
- Illiana Heights
- Illinois City
- Illiopolis
- Imbs
- Ina
- Independence
- Indian Boundary
- Indian Chase Meadows
- Indian Creek
- Indian Creek
- Indian Head Park
- Indian Hill
- Indian Island
- Indian Island
- Indian Island
- Indian Oaks
- Indian Oaks
- Indian Ridge
- Indian Spring
- Indian Trails
- Indianola
- Industry
- Ingalls Park
- Ingalton