| Irkaia | Industrial Metal | Nafarroa | |
| Iroy | Heavy Metal | Araba | |
| Izei | Rock/Metal | Gipuzkoa | |
| Jhëit | Black Metal | Bizkaia | |
| Kabbalah | Doom/Heavy/Rock | Nafarroa | |
| Kaixton | Thrash/Death Metal | Bizkaia | |
| Kartzarot | Heavy Metal | Bizkaia | |
| Katar | Metalcore | Araba | |
| Katez | Metal | Nafarroa | |
| Kauce | Heavy Rock | Bizkaia | |
| Keziah | Post Metal | Bizkaia | |
| Khamul | Metal | Nafarroa | |
| Kharmia | Heavy Metal | Nafarroa | |
| Khous | Metal | Nafarroa | |
| Khymaira | Heavy Metal | Gipuzkoa | |
| Killers | Speed Metal | Lapurdi | |
| Killiki | Death Metal | Nafarroa | |
| Killwolf | Hard Rock | Gipuzkoa | |
| Klown | Metal | Bizkaia | |
| Knives | Death'n'roll | Bizkaia | |
| Kohatu | Metal | Bizkaia | |
| Koma | Thrash'n'roll | Nafarroa | |
| Konbenio del Metal | Heavy Rock | Gipuzkoa | |
| Krait | Heavy/Power Metal | Gipuzkoa | |
| La Rebelión de las Gárgolas | Heavy/Progressive Metal | Bizkaia | |
| La Sonrisa Metálica | Rock/Metal | Nafarroa | |
| Lagash | Heavy Metal | Gipuzkoa | |
| Lampr3a | Technical Death Metal | Gipuzkoa | |
| Lappa | Pop Metal | Gipuzkoa | |
| Late To Scream | Metal | Bizkaia |
