| City | 2026 Pop. ↓ |
|---|---|
| Sevilla | 689,481 |
| Sabadell | 227,267 |
| Santa Cruz de Tenerife | 212,618 |
| Santander | 175,914 |
| San Cristobal de La Laguna | 161,655 |
| Salamanca | 146,479 |
| Santa Coloma de Gramenet | 124,721 |
| Santiago de Compostela | 101,581 |
| Sant Cugat del Valles | 99,179 |
| San Sebastian de los Reyes | 98,258 |
| San Fernando | 92,994 |
| Sant Boi de Llobregat | 85,880 |
| Santa Lucia de Tirajana | 79,522 |
| Sagunt/Sagunto | 74,370 |
| Sanlucar de Barrameda | 70,162 |
| Sant Vicent del Raspeig/San Vicente del Raspeig | 60,572 |
| San Bartolome de Tirajana | 54,540 |
| Siero | 53,371 |
| Segovia | 52,450 |