| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Sebundoy | city | Sucumbios | Ecuador | 0.50 | -77.50 | 5029 | 2122 |
| Secas | city | Pichincha | Ecuador | -0.45 | -78.33 | 11748 | 2980 |
| Secoya | city | Sucumbios | Ecuador | 0.05 | -76.61 | 1053 | 2553 |
| Segal | city | Guayas | Ecuador | -2.38 | -79.85 | 0 | 2415 |
| Segunda | city | Los Rios | Ecuador | -0.79 | -79.25 | 990 | 5057 |
| Segundo Respaldo | city | Santo Domingo de los Tsachilas | Ecuador | -0.42 | -79.24 | 2509 | 4501 |
| Seis de Enero | city | Santo Domingo de los Tsachilas | Ecuador | -0.16 | -79.05 | 2618 | 2546 |
| Seis de Julio de Cuellaje | city | Imbabura | Ecuador | 0.40 | -78.53 | 6709 | 2169 |
| Selel | city | Azuay | Ecuador | -2.68 | -78.63 | 8389 | 6099 |
| Selva Alegre | city | Loja | Ecuador | -3.55 | -79.34 | 7808 | 3535 |
| Selva Alegre | city | Esmeraldas | Ecuador | 0.93 | -78.86 | 830 | 2396 |
| Selva Alegre | city | Manabi | Ecuador | -0.50 | -80.32 | 830 | 4723 |
| Selva Alegre | city | Imbabura | Ecuador | 0.25 | -78.57 | 5869 | 2154 |
| Selva Alegre | city | Pichincha | Ecuador | -0.35 | -78.43 | 8772 | 71715 |
| Selvalegre | city | Imbabura | Ecuador | 0.25 | -78.57 | 5869 | 2154 |
| Selvayacu | city | Sucumbios | Ecuador | 0.09 | -76.02 | 830 | 149 |
| Seman | city | Azuay | Ecuador | -2.74 | -78.76 | 8802 | 21408 |
| Semen | city | Guayas | Ecuador | -1.87 | -79.87 | 82 | 16367 |
| Semeria | city | Azuay | Ecuador | -2.90 | -79.03 | 8389 | 213783 |
| Semir | city | Guayas | Ecuador | -1.68 | -80.02 | 108 | 19741 |
| Semita | city | Guayas | Ecuador | -1.92 | -79.67 | 75 | 13907 |
| Senegal | city | Loja | Ecuador | -4.37 | -79.88 | 2509 | 4222 |
| Senor Calderon | city | Azuay | Ecuador | -2.95 | -79.18 | 10951 | 3263 |
| Senor Crespo | city | Azuay | Ecuador | -2.88 | -79.12 | 10944 | 12118 |
| Senor Farfan | city | Azuay | Ecuador | -2.88 | -79.07 | 8523 | 111009 |
| Senor Terreros | city | Azuay | Ecuador | -2.90 | -79.05 | 8389 | 170678 |
| Senora Carrion | city | Azuay | Ecuador | -2.85 | -79.13 | 10908 | 5739 |
| Sentencia | city | Azuay | Ecuador | -2.82 | -78.78 | 8389 | 24632 |
| Sequer | city | Loja | Ecuador | -3.48 | -79.44 | 9228 | 2864 |
| Sequita | city | Manabi | Ecuador | -1.03 | -80.58 | 830 | 11587 |
| Serrac | city | Azuay | Ecuador | -3.11 | -78.92 | 8677 | 6874 |
| Serrano | city | Manabi | Ecuador | 0.13 | -79.66 | 843 | 2801 |
| Sertag | city | Azuay | Ecuador | -2.88 | -78.77 | 8389 | 36420 |
| Seurcel | city | Azuay | Ecuador | -3.47 | -79.30 | 4189 | 2821 |
| Sevilla | city | Chimborazo | Ecuador | -2.27 | -78.82 | 10908 | 6913 |
| Sevilla | city | Sucumbios | Ecuador | 0.09 | -77.13 | 1699 | 3602 |
| Sevilla Don Bosco | city | Morona-Santiago | Ecuador | -2.29 | -78.08 | 4189 | 2073 |
| Sevilla de Oro | city | Azuay | Ecuador | -2.80 | -78.65 | 10068 | 4982 |
| Seymour | city | Galapagos | Ecuador | -0.42 | -90.27 | 3 | 0 |
| Señor Moreno | city | Azuay | Ecuador | -2.88 | -79.12 | 10944 | 12118 |
| Señor Moscoso | city | Azuay | Ecuador | -2.88 | -78.97 | 8389 | 200473 |
| Señor Vélez | city | Azuay | Ecuador | -2.95 | -79.15 | 10446 | 3458 |
| Señorío de Pechance | city | Manabi | Ecuador | -0.70 | -80.09 | 347 | 47659 |