| San Marcos to Security-Widefield (Colorado) | 796.62 mi (1,282.03 km) |
| San Marcos to Sedalia (Missouri) | 1,389.19 mi (2,235.68 km) |
| San Marcos to Sedro-Woolley (Washington) | 1,094.18 mi (1,760.91 km) |
| San Marcos to Seguin (Texas) | 1,157.56 mi (1,862.91 km) |
| San Marcos to Selden (New York) | 2,465.85 mi (3,968.40 km) |
| San Marcos to Selma (Alabama) | 1,745.63 mi (2,809.31 km) |
| San Marcos to Selma (California) | 274.78 mi (442.21 km) |
| San Marcos to Selma (Texas) | 1,137.77 mi (1,831.07 km) |
| San Marcos to Seminole (Florida) | 2,070.49 mi (3,332.14 km) |
| San Marcos to Seven Hills (Ohio) | 2,018.00 mi (3,247.66 km) |
| San Marcos to Seven Oaks (South Carolina) | 2,063.93 mi (3,321.58 km) |
| San Marcos to Severn (Maryland) | 2,277.28 mi (3,664.92 km) |
| San Marcos to Severna Park (Maryland) | 2,284.21 mi (3,676.08 km) |
| San Marcos to Sevierville (Tennessee) | 1,913.38 mi (3,079.28 km) |
| San Marcos to Seymour (Indiana) | 1,783.93 mi (2,870.95 km) |
