| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Sacanche | city | Departamento de San Martin | Peru | -7.08 | -76.73 | 1174 | 6556 |
| Sacareto | city | Departamento de San Martin | Peru | -6.30 | -75.73 | 649 | 666 |
| San Agustín | city | Departamento de San Martin | Peru | -8.16 | -76.47 | 1594 | 4177 |
| San Antonio | city | Departamento de San Martin | Peru | -8.57 | -76.54 | 2591 | 959 |
| San Antonio | city | Departamento de San Martin | Peru | -8.53 | -76.49 | 2293 | 2991 |
| San Antonio | city | Departamento de San Martin | Peru | -5.70 | -77.49 | 2900 | 1531 |
| San Antonio | city | Departamento de San Martin | Peru | -6.37 | -76.35 | 1886 | 6830 |
| San Antonio | city | Departamento de San Martin | Peru | -7.25 | -76.73 | 1033 | 7523 |
| San Antonio | city | Departamento de San Martin | Peru | -8.51 | -76.41 | 2634 | 869 |
| San Antonio de Padua | city | Departamento de San Martin | Peru | -8.57 | -76.54 | 2591 | 959 |
| San Antonio de Paujilzapa | city | Departamento de San Martin | Peru | -6.78 | -76.42 | 1253 | 1563 |
| San Carlos | city | Departamento de San Martin | Peru | -6.64 | -76.43 | 964 | 2147 |
| San Carlos | city | Departamento de San Martin | Peru | -7.04 | -76.50 | 958 | 4545 |
| San Carlos | city | Departamento de San Martin | Peru | -8.43 | -76.41 | 1853 | 6641 |
| San Carlos | city | Departamento de San Martin | Peru | -5.87 | -77.43 | 5059 | 4567 |
| San Cristobal de Sisa | city | Departamento de San Martin | Peru | -7.00 | -76.44 | 938 | 3886 |
| San Cristóbal | city | Departamento de San Martin | Peru | -6.18 | -76.23 | 984 | 2907 |
| San Fernando | city | Departamento de San Martin | Peru | -6.60 | -76.45 | 997 | 2847 |
| San Fernano | city | Departamento de San Martin | Peru | -5.90 | -77.27 | 2598 | 7662 |
| San Francisco | city | Departamento de San Martin | Peru | -5.78 | -77.32 | 2624 | 1822 |
| San Francisco | city | Departamento de San Martin | Peru | -8.51 | -76.45 | 2283 | 2611 |
| San Francisco | city | Departamento de San Martin | Peru | -6.58 | -76.42 | 977 | 20295 |
| San Hilarión | city | Departamento de San Martin | Peru | -7.02 | -76.46 | 948 | 4066 |
| San Jose | city | Departamento de San Martin | Peru | -5.97 | -77.29 | 3005 | 7878 |
| San Jose | city | Departamento de San Martin | Peru | -5.69 | -77.37 | 2795 | 52448 |
| San Jose | city | Departamento de San Martin | Peru | -6.10 | -77.06 | 2946 | 5743 |
| San Jose de Potrero | city | Departamento de San Martin | Peru | -6.15 | -77.02 | 3415 | 8525 |
| San Jose de Sisa | city | Departamento de San Martin | Peru | -6.62 | -76.65 | 2486 | 6382 |
| San Juan | city | Departamento de San Martin | Peru | -7.06 | -76.44 | 974 | 2221 |
| San Juan | city | Departamento de San Martin | Peru | -5.86 | -77.34 | 3166 | 7925 |
| San Juan | city | Departamento de San Martin | Peru | -7.17 | -76.38 | 1325 | 532 |
| San Juan | city | Departamento de San Martin | Peru | -6.53 | -76.37 | 987 | 67040 |
| San Juan de Tocache | city | Departamento de San Martin | Peru | -8.18 | -76.51 | 1532 | 4366 |
| San Julián | city | Departamento de San Martin | Peru | -7.68 | -76.77 | 1243 | 595 |
| San Juán de Tangomi | city | Departamento de San Martin | Peru | -6.04 | -77.13 | 2627 | 8722 |
| San Lorenzo | city | Departamento de San Martin | Peru | -6.19 | -77.10 | 2841 | 4855 |
| San Marcos | city | Departamento de San Martin | Peru | -6.22 | -77.12 | 2568 | 3994 |
| San Martin | city | Departamento de San Martin | Peru | -6.50 | -76.37 | 1397 | 56569 |
| San Martín | city | Departamento de San Martin | Peru | -6.50 | -76.75 | 2119 | 2522 |
| San Miguel | city | Departamento de San Martin | Peru | -6.21 | -77.06 | 3923 | 5939 |
| San Miguel | city | Departamento de San Martin | Peru | -6.38 | -76.67 | 1902 | 11516 |
| San Miguel | city | Departamento de San Martin | Peru | -8.57 | -76.43 | 3152 | 899 |
| San Miguel | city | Departamento de San Martin | Peru | -5.85 | -77.38 | 3923 | 6962 |
| San Pablo | city | Departamento de San Martin | Peru | -6.80 | -76.58 | 1266 | 2959 |
| San Pedro | city | Departamento de San Martin | Peru | -7.38 | -76.43 | 1282 | 149 |
| San Rafael | city | Departamento de San Martin | Peru | -5.85 | -77.09 | 2513 | 2235 |
| San Rafael | city | Departamento de San Martin | Peru | -7.04 | -76.47 | 941 | 3636 |
| Sanchima | city | Departamento de San Martin | Peru | -7.18 | -76.97 | 1305 | 149 |
| Santa Bárbara | city | Departamento de San Martin | Peru | -7.18 | -76.97 | 1305 | 149 |
| Santa Catalina | city | Departamento de San Martin | Peru | -5.99 | -76.97 | 2388 | 1662 |
| Santa Clara | city | Departamento de San Martin | Peru | -5.89 | -77.29 | 2673 | 8364 |
| Santa Cruz de Shanao | city | Departamento de San Martin | Peru | -6.35 | -76.67 | 1781 | 12122 |
| Santa Elena | city | Departamento de San Martin | Peru | -8.44 | -76.42 | 1916 | 5363 |
| Santa Elena | city | Departamento de San Martin | Peru | -5.99 | -77.19 | 2496 | 20344 |
| Santa Elena | city | Departamento de San Martin | Peru | -6.22 | -75.75 | 669 | 2248 |
| Santa Elena | city | Departamento de San Martin | Peru | -7.22 | -76.49 | 1263 | 422 |
| Santa Isabel | city | Departamento de San Martin | Peru | -8.46 | -76.44 | 1935 | 4195 |
| Santa Lucia | city | Departamento de San Martin | Peru | -6.33 | -75.70 | 656 | 760 |
| Santa Lucia | city | Departamento de San Martin | Peru | -8.35 | -76.39 | 1640 | 5377 |
| Santa Luisa | city | Departamento de San Martin | Peru | -6.56 | -76.33 | 941 | 40005 |
| Santa Rosa | city | Departamento de San Martin | Peru | -6.09 | -77.24 | 3172 | 13568 |
| Santa Rosa | city | Departamento de San Martin | Peru | -6.63 | -75.63 | 921 | 745 |
| Santa Rosa | city | Departamento de San Martin | Peru | -6.75 | -76.34 | 895 | 1752 |
| Santa Rosa | city | Departamento de San Martin | Peru | -8.24 | -76.40 | 1669 | 4633 |
| Santa Rosa | city | Departamento de San Martin | Peru | -6.68 | -76.62 | 1971 | 2627 |
| Santa Rosa | city | Departamento de San Martin | Peru | -7.18 | -76.35 | 1364 | 558 |
| Santa Rosa | city | Departamento de San Martin | Peru | -6.19 | -77.09 | 3047 | 5420 |
| Santa Rosa | city | Departamento de San Martin | Peru | -5.72 | -77.37 | 2654 | 52208 |
| Santa Rosa de Cumbaza | city | Departamento de San Martin | Peru | -6.53 | -76.38 | 997 | 69490 |
| Santa Rosa de Oromina | city | Departamento de San Martin | Peru | -6.10 | -77.03 | 3064 | 6851 |
| Santa Rosita de Upaquihua | city | Departamento de San Martin | Peru | -6.73 | -76.42 | 994 | 1405 |
| Santa Zenobia | city | Departamento de San Martin | Peru | -6.58 | -76.30 | 800 | 11119 |
| Santafe | city | Departamento de San Martin | Peru | -6.03 | -77.28 | 3326 | 8362 |
| Santillo | city | Departamento de San Martin | Peru | -6.20 | -77.16 | 2588 | 5404 |
| Santo Domingo | city | Departamento de San Martin | Peru | -6.07 | -77.11 | 2677 | 4254 |
| Saposoa | city | Departamento de San Martin | Peru | -6.93 | -76.80 | 1309 | 10160 |
| Sapote | city | Departamento de San Martin | Peru | -5.94 | -77.03 | 2513 | 5331 |
| Sauce | city | Departamento de San Martin | Peru | -6.69 | -76.21 | 1040 | 6128 |
| Sausi | city | Departamento de San Martin | Peru | -6.69 | -76.21 | 1040 | 6128 |
| Segunda Jerusalén Azunguillo | city | Departamento de San Martin | Peru | -5.99 | -77.28 | 3083 | 8320 |
| Selva Alegre | city | Departamento de San Martin | Peru | -6.23 | -77.15 | 2746 | 3514 |
| Setico Tipisca | city | Departamento de San Martin | Peru | -6.28 | -75.67 | 675 | 517 |
| Setico Tipishca | city | Departamento de San Martin | Peru | -6.28 | -75.67 | 675 | 517 |
| Shambayacu | city | Departamento de San Martin | Peru | -7.00 | -76.17 | 1118 | 960 |
| Shamboyacu | city | Departamento de San Martin | Peru | -7.13 | -76.03 | 2611 | 975 |
| Shamboyacu | city | Departamento de San Martin | Peru | -5.79 | -77.37 | 2988 | 2222 |
| Shanao | city | Departamento de San Martin | Peru | -6.35 | -76.67 | 1781 | 12122 |
| Shanusi | city | Departamento de San Martin | Peru | -6.12 | -76.25 | 721 | 2528 |
| Shapaja | city | Departamento de San Martin | Peru | -8.30 | -76.36 | 1624 | 5064 |
| Shapaja | city | Departamento de San Martin | Peru | -6.58 | -76.26 | 784 | 2355 |
| Shapaya | city | Departamento de San Martin | Peru | -6.58 | -76.26 | 784 | 2355 |
| Shatuyacu | city | Departamento de San Martin | Peru | -6.57 | -76.31 | 853 | 19618 |
| Shepte | city | Departamento de San Martin | Peru | -7.42 | -76.82 | 1955 | 187 |
| Shilco | city | Departamento de San Martin | Peru | -8.44 | -76.81 | 4826 | 149 |
| Shimpiyacu | city | Departamento de San Martin | Peru | -5.84 | -77.10 | 2555 | 2235 |
| Shismayacu | city | Departamento de San Martin | Peru | -8.23 | -76.45 | 1561 | 4296 |
| Silco | city | Departamento de San Martin | Peru | -8.44 | -76.81 | 4826 | 149 |
| Sinamal | city | Departamento de San Martin | Peru | -5.96 | -77.22 | 2562 | 11645 |
| Sion | city | Departamento de San Martin | Peru | -7.65 | -76.77 | 1272 | 596 |
| Sion | city | Departamento de San Martin | Peru | -7.67 | -76.78 | 1210 | 596 |
| Sisa | city | Departamento de San Martin | Peru | -6.62 | -76.65 | 2486 | 6382 |
| Sol Naciente | city | Departamento de San Martin | Peru | -6.23 | -77.06 | 4130 | 4970 |
| Soritor | city | Departamento de San Martin | Peru | -6.14 | -77.10 | 2916 | 4201 |
| Subyaquiru | city | Departamento de San Martin | Peru | -5.95 | -76.91 | 3067 | 2220 |
| Sucllaquiro | city | Departamento de San Martin | Peru | -5.95 | -76.91 | 3067 | 2220 |
| Surquillo | city | Departamento de San Martin | Peru | -5.80 | -77.27 | 2575 | 3500 |