| K | | United States |
| K.D.T. Records | | |
| K.O.City Studio | | United States |
| K7 | | |
| Kadath | | |
| Kadef | | Germany |
| Kahlschlag | | |
| Kaisettes-Kaisettes | | |
| Kaissettes | | Netherlands |
| Kangyur Recordings | | |
| Kanker Kommando (K.a.K.) | 1980- | Belgium |
| Kaon | | |
| Kaos Music | | |
| KAPPAA PROD. | | |
| Kartell | | Germany |
| Kassette Kult Tapes | | |
| Kassetto Fix | | Germany |
| Katakomb Productions | | France |
| Katastrophenschutz Tapes | | |
| Katharos Foundation | | Netherlands |
| Kaw Tapes | | |
| KD | | United Kingdom |
| KDF | | |
| Keeler Prod | | Canada |
| Kein Zurück Label | | Germany |
| Ken Rubenstein | | |
| Kenaz | | |
| Kenneth Anger | | |
| Kentucky Fried Royalty | | |
| Killzone Music | | |
| Kimbaze | | Germany |
| Kinematograph Tapes | | United Kingdom |
| Kinky Kassettes | | Netherlands |
| Kinky Music Institute | | |
| Kinky Musik Institute | | Japan |
| Kinky Tape Collection | | Japan |
| Kino aus Der Kassette | | Germany |
| Kino-Tone Recordings | | Netherlands |
| Kitti Tapes | | United States |
| KK Records | | Belgium |
| Klangbad | | |
| KlangFarBe | | Germany |
| Klanggalerie | | |
| Klangkrieg | | |
| Klangkäfig | | Germany |
| Klangstelle 2 | | |
| Klank Productions | | |
| Klappstuhl Records | | Germany |
| Klar! 80 | | Germany |
| Kleo | | Belgium |
| Klett Verlag | | |
| Klex Musik | | Germany |
| Klinker Zoundz | | United Kingdom |
| KMP K! | | United Kingdom |
| Knallschote | | Germany |
| Knallsyndikatet / Idiot Press | | Norway |
| Knoblauch Mief / Sado Maso Tapes | | |
| Knoblauch Records | | |
| Koesette Snacks | | Germany |
| Koital Kult Product | | Germany |
| Koma 995 | | |
| Komakino | | Germany |
| Kommt noch Schlimmer Tapes | | Germany |
| Kompakt Produkte | | Germany |
| Konduktör Rekords | | Sweden |
| KOPROD | | Switzerland |
| Korm Plastics | | Netherlands |
| KPFA | | |
| KPFA Radio Program | | United States |
| Krach Tapes | | Germany |
| Krash-Verlag | | Germany |
| Kremlin | | Netherlands |
| Kronchtadt Tapes | | France |
| Kronotop | | |
| Kröten Kassetten | | Germany |
| Kubitsuri Tapes | | Japan |
| Kubus Kassettes | | Netherlands |
| Kubus Kassettes, Aeon | | |
| Kubus-Kassettes | | |
| Kufucheops | | Netherlands |
| Kuklos | | |
| Kult Production | | |
| KULTuhr Kassette | | |
| Kulturbehörde Hamburg | | |
| Kulturinstutisjonen Piivv | | Norway |
| Kulturkreis TYR | | |
| Kunst = Kapital | | |
| Kunst Parterre | | |
| Kunsthalle Frankfurt | | |
| Kunsthalle Nürnberg | | |
| Kunstklang | | |
| Kunta Kinte Tapes | | Germany |
| Kurort Productions | | |
| Kvern Music | | |
| Kx4 | | United States |
| Köhler Privatsammlung | | |