| Westbrook to Siloam Springs (Arkansas) | 1,375.64 mi (2,213.88 km) |
| Westbrook to Silver Firs (Washington) | 2,465.28 mi (3,967.49 km) |
| Westbrook to Silver Spring (Maryland) | 473.73 mi (762.39 km) |
| Westbrook to Silver Springs Shores (Florida) | 1,195.49 mi (1,923.96 km) |
| Westbrook to Silverdale (Washington) | 2,492.52 mi (4,011.32 km) |
| Westbrook to Silverton (Oregon) | 2,545.85 mi (4,097.14 km) |
| Westbrook to Simi Valley (California) | 2,640.28 mi (4,249.12 km) |
| Westbrook to Simpsonville (South Carolina) | 887.02 mi (1,427.52 km) |
| Westbrook to Sioux City (Iowa) | 1,310.81 mi (2,109.54 km) |
| Westbrook to Sioux Falls (South Dakota) | 1,313.85 mi (2,114.44 km) |
| Westbrook to Skokie (Illinois) | 886.23 mi (1,426.25 km) |
| Westbrook to Sleepy Hollow (New York) | 254.01 mi (408.79 km) |
| Westbrook to Slidell (Louisiana) | 1,410.47 mi (2,269.94 km) |
| Westbrook to Smithfield (North Carolina) | 706.90 mi (1,137.64 km) |
| Westbrook to Smithfield (Utah) | 2,085.59 mi (3,356.43 km) |
