5 cities
| City | County | 2025 Pop. ↓ |
|---|---|---|
| Ledyard | Southeastern CT Planning Region | 15,539 |
| Litchfield | Northwest Hills Planning Region | 8,317 |
| Lebanon | Southeastern CT Planning Region | 7,088 |
| Lisbon | Southeastern CT Planning Region | 4,220 |
| Lyme | Lower CT River Valley Planning Region | 2,435 |