| Sabotaje | Heavy Metal | Bizkaia | |
| Saddict | Metal | Lapurdi | |
| Samarithan | Doom Metal | Bizkaia | |
| Sanngre | Thrashcore/Hardcore punk | Bizkaia | |
| Satirah | Thrash Metal | Bizkaia | |
| Scorn | Thrash/Death Metal | Lapurdi | |
| Sealed | Rock/Metal | Bizkaia | |
| Sentimen Beltza | Black Metal | Araba | |
| Sepulchral | Death Metal | Bizkaia | |
| Sevicia | Metal | Bizkaia | |
| Shallow Waters | Post Black Metal | Gipuzkoa | |
| Shintra | Post Metal | Bizkaia | |
| Shut You Out | Post Metal Instrumentala | Bizkaia | |
| Sinmas | Thrashcore | Bizkaia | |
| Sinner Rage | Heavy Metal | Araba | |
| Sinpekado | Thrashcore | Bizkaia | |
| Sixmika | Groove Metal | Araba | |
| Skin Tortured | Death Metal | Bizkaia | |
| Soa | Death/Thrash Metal | Gipuzkoa | |
| Somnium Surge | Metal | Bizkaia | |
| Sönambula | Doom/Death Metal | Bizkaia | |
| Song Of Anhubis | Rock/Metal | Bizkaia | |
| Sons of Decay | Thrash/Black Metal | Gipuzkoa | |
| Sorgerth | Death Metal | Bizkaia | |
| Sorhots | Rock/Metal | Lapurdi | |
| Soulitude | Heavy/Power Metal | Bizkaia | |
| Soziedad Alkoholika | Crossover | Araba | |
| Spl33n | Metal | Lapurdi | |
| Starbeast | Hard rock | Nafarroa | |
| Stolen Soul | Groove Metal | Bizkaia |