| ILoveRibs! | — |
| Imagine Music | — |
| Imposible Records | 1984 |
| In My Heart Empire | — |
| In the Morningside Records | — |
| Inferno Recordings | 2006 |
| InoQuo | — |
| Insolent Tracks | — |
| Irregular | — |
| Itofarm | 2007 |
| Jaja Records | 1982 |
| JMB Ediciones | — |
| Joker Records | — |
| Julio's Records | — |
| Junk Records | — |
| K Industria Cultural SL | — |
| Kankana Records | — |
| Kantalas Mob | — |
| Klitekture | — |
| KMC | — |
| Koka Music | — |
| La Agonía de Vivir | — |
| La Alegría de Vivir | — |
| La Fábrica Magnética | 1988 |
| La Huella Sonora | — |
| La Idea | — |
| La Madriguera Records | — |
| Locomotive Music | — |
| Locomotive Records | 2004 |
| Los Enanos Gigantes | — |
| Lubicán Records | — |
| Lyricon | 1991 |
| Magna Music | — |
| Mainout | — |
| Margen | — |
| Marxophone | 2010 |
| Mass Records | — |
| Metal Bastard Enterprises | 15 de julio de 2016 |
| Metales Preciosos Musica & Discos | — |
| Mil A Gritos Records | — |
| Minifunk | 1996 |
| MITUB3R MUSIC | 1 de febrero de 2026 |
| Moby Disk Records | — |
| Mondegreen Records | — |
| Mondongo Canibale Records | — |
| Music for The Other People Place | — |
| Musikra Records | — |
| Mutant-E Records | — |