| Lee Kore | Hardcore/Metal | Gipuzkoa | |
| Legacy of the Seas | Epic Power Metal | Gipuzkoa | |
| Legalize Murder | Thrash Metal | Nafarroa | |
| Legen Beltza | Thrash Metal | Gipuzkoa | |
| Leize | Heavy Rock | Gipuzkoa | |
| Lifelost | Black Metal | Bizkaia | |
| Lined | Melodic Death/Thrash Metal | Gipuzkoa | |
| Lord Witch | Power Metal | Gipuzkoa | |
| Los Cojones | Heavy Metal | Bizkaia | |
| Lotura | Rock/Metal alternatiboa | Bizkaia | |
| Lubaki | Rap Metal | Nafarroa | |
| Lurgorr | Thrashcore | Bizkaia | |
| Malevolic | Black Metal | Bizkaia | |
| Mandrágora Negra | Heavy/Power Metal | Gipuzkoa | |
| Matutano | Death/Grindcore | Bizkaia | |
| MDMA | Brutal Death Metal | Bizkaia | |
| Meliora | Hard Rock/Heavy Metal | Gipuzkoa | |
| Melmak | Metal/Sludge/Doom | Bizkaia | |
| Meriur | Metalcore | Nafarroa | |
| Mi Dulce Geisha | Rock/Metal | Bizkaia | |
| Midnight Road | Hard Rock | Bizkaia | |
| Mise en Abyme | Prog Metal | Gipuzkoa | |
| Mitosia | Rock/Metal | Bizkaia | |
| Mosh | Metal/Rock | Nafarroa | |
| Mørgue | Thrashcore | Gipuzkoa | |
| Ms. Missery | Alt rock/metal | Bizkaia | |
| Mundo Rata | Thrash/Death Metal | Araba | |
| Mutilated Judge | Grindcore | Bizkaia | |
| My Sweet Torment | Black/Death Metal | Bizkaia | |
| Nakkiga | Pagan Black Metal | Araba |
