| San Mateo to Silver Firs (Washington) | 712.49 mi (1,146.64 km) |
| San Mateo to Silver Spring (Maryland) | 2,433.02 mi (3,915.57 km) |
| San Mateo to Silver Springs Shores (Florida) | 2,378.95 mi (3,828.55 km) |
| San Mateo to Silverdale (Washington) | 699.07 mi (1,125.04 km) |
| San Mateo to Silverton (Oregon) | 515.37 mi (829.41 km) |
| San Mateo to Simi Valley (California) | 302.11 mi (486.20 km) |
| San Mateo to Simpsonville (South Carolina) | 2,226.65 mi (3,583.45 km) |
| San Mateo to Sioux City (Iowa) | 1,407.39 mi (2,264.97 km) |
| San Mateo to Sioux Falls (South Dakota) | 1,398.92 mi (2,251.34 km) |
| San Mateo to Skokie (Illinois) | 1,848.42 mi (2,974.74 km) |
| San Mateo to Sleepy Hollow (New York) | 2,567.31 mi (4,131.69 km) |
| San Mateo to Slidell (Louisiana) | 1,920.83 mi (3,091.28 km) |
| San Mateo to Smithfield (North Carolina) | 2,422.47 mi (3,898.58 km) |
| San Mateo to Smithfield (Utah) | 630.50 mi (1,014.70 km) |
| San Mateo to Smithville (Missouri) | 1,499.89 mi (2,413.84 km) |
