| South San Francisco to Siloam Springs (Arkansas) | 1,538.19 mi (2,475.47 km) |
| South San Francisco to Silver Firs (Washington) | 705.55 mi (1,135.48 km) |
| South San Francisco to Silver Spring (Maryland) | 2,436.65 mi (3,921.41 km) |
| South San Francisco to Silver Springs Shores (Florida) | 2,385.09 mi (3,838.43 km) |
| South San Francisco to Silverdale (Washington) | 691.92 mi (1,113.55 km) |
| South San Francisco to Silverton (Oregon) | 508.12 mi (817.75 km) |
| South San Francisco to Simi Valley (California) | 311.26 mi (500.93 km) |
| South San Francisco to Simpsonville (South Carolina) | 2,231.60 mi (3,591.41 km) |
| South San Francisco to Sioux City (Iowa) | 1,410.21 mi (2,269.51 km) |
| South San Francisco to Sioux Falls (South Dakota) | 1,401.27 mi (2,255.13 km) |
| South San Francisco to Skokie (Illinois) | 1,851.47 mi (2,979.66 km) |
| South San Francisco to Sleepy Hollow (New York) | 2,570.30 mi (4,136.50 km) |
| South San Francisco to Slidell (Louisiana) | 1,927.36 mi (3,101.78 km) |
| South San Francisco to Smithfield (North Carolina) | 2,427.00 mi (3,905.87 km) |
| South San Francisco to Smithfield (Utah) | 631.95 mi (1,017.03 km) |
