| Sauquillo de Cabezas | Segovia | 40351 | 1 |
| Saus, Camallera i Llampaies | Girona | 17465 | 1 |
| Sauzal, El | Santa Cruz de Tenerife | 38359–38360 | 2 |
| Sax | Alicante | 03630 | 1 |
| Sayalonga | Málaga | 29752 | 1 |
| Sebúlcor | Segovia | 40340–40380 | 2 |
| Seca, La | Valladolid | 47491 | 1 |
| Secastilla | Huesca | 22391–22439 | 2 |
| Sedella | Málaga | 29715 | 1 |
| Sediles | Zaragoza | 50334 | 1 |
| Segart | Valencia | 46592 | 1 |
| Segorbe | Castellón | 12412 | 1 |
| Segovia | Segovia | 40001–40195 | 9 |
| Segura de la Sierra | Jaén | 23293–23379 | 5 |
| Segura de León | Badajoz | 06270 | 1 |
| Segura de Toro | Cáceres | 10739 | 1 |
| Segurilla | Toledo | 45621 | 1 |
| Seira | Huesca | 22463–22464 | 2 |
| Selas | Guadalajara | 19346 | 1 |
| Selaya | Cantabria | 39696 | 1 |
| Sella | Alicante | 03579 | 1 |
| Selva | Illes Balears | 07313–07369 | 4 |
| Sena | Huesca | 22230 | 1 |
| Sena de Luna | León | 24146 | 1 |
| Sencelles | Illes Balears | 07140–07511 | 4 |
| Senija | Alicante | 03729 | 1 |
| Seno | Teruel | 44561 | 1 |
| Senterada | Lleida | 25214–25514 | 2 |
| Sentmenat | Barcelona | 08181 | 1 |
| Senyera | Valencia | 46669 | 1 |
| Senés | Almería | 04213 | 1 |
| Senés de Alcubierre | Huesca | 22253 | 1 |
| Sepulcro-Hilario | Salamanca | 37638 | 1 |
| Sepúlveda | Segovia | 40300–40317 | 2 |
| Sequera de Fresno | Segovia | 40517 | 1 |
| Sequeros | Salamanca | 37650 | 1 |
| Serinyà | Girona | 17852 | 1 |
| Serra | Valencia | 46118 | 1 |
| Serrada | Valladolid | 47231–47239 | 2 |
| Serradilla | Cáceres | 10530–10695 | 2 |
| Serradilla del Arroyo | Salamanca | 37531–37596 | 2 |
| Serradilla del Llano | Salamanca | 37530 | 1 |
| Serranillos del Valle | Madrid | 28979 | 1 |
| Serrato | Málaga | 29400–29471 | 2 |
| Serrejón | Cáceres | 10528 | 1 |
| Seròs | Lleida | 25183 | 1 |
| Serón | Almería | 04890–04899 | 2 |
| Ses Salines | Illes Balears | 07638–07640 | 2 |
| Sesa | Huesca | 22110 | 1 |
| Seseña | Toledo | 45223–45224 | 2 |
| Sesma | Navarra | 31293 | 1 |
| Sestao | Bizkaia | 48910 | 1 |
| Sestrica | Zaragoza | 50248–50249 | 2 |
| Setcases | Girona | 17869 | 1 |
| Setenil de las Bodegas | Cádiz | 11692 | 1 |
| Setiles | Guadalajara | 19324 | 1 |
| Seva | Barcelona | 08553–08554 | 2 |
| Seville | Sevilla | 41001–41500 | 22 |
| Sevilleja de la Jara | Toledo | 45671–45673 | 3 |
| Sidamon | Lleida | 25222 | 1 |