- Hindemith, Paul
- Hoffmeister, Leon Abbott
- Hoiby, Lee
- Holmès, Augusta
- Holmes, Brian
- Holst, Gustav
- Holstein, Franz von
- Hölzel, Gustav
- Honegger, Arthur
- Hook, James
- Hopkins, Antony
- Hopkinson, Francis
- Horder, Mervyn
- Hösel, Kurt
- Hovhaness, Alan
- Howells, Herbert Norman
- Hubay, Jenö
- Hüe, Georges
- Huertos, Pablo
- Hugh-Jones, Elaine
- Hughes, Herbert
- Huhn, Bruno Siegfried
- Hume, Tobias
- Hummel, Ferdinand
- Humperdinck, Engelbert
- Humphreys, Don
- Hundley, Richard
- Huss, Henry Holden
- Ibert, Jacques
- Inzenga, José
- Iradier, Sebastián
- Ireland, John
- Ives, Charles Edward
- Jaëll, Marie
- Jahn, Otto
- Jaques-Dalcroze, Emile
- Jensen, Adolf
- Joachim, Joseph
- Johnson, Hall
- Johnson, Robert
- Jommelli, Niccolo
- Jonas, Alberto
- Jones, Robert
- Jongen, Joseph
- Joseffy, Rafael
- Josten, Werner Erich
- Jude, W. H.
- Kagen, Sergius
- Kahn, Robert
- Kalivoda, Jan
- Karg-Elert, Sigfrid
- Kauffmann, Emil
- Kayser, Philipp Christoph
- Keel, Frederick
- Kempff, Wilhelm
- Kernochan, Marshall Rutgers
- Kienzl, Wilhelm
- Kilenyi, Edward
- King, Betty Jackson
- Kirlin, June Caldwell
- Kittl, Jan Bedrich
- Kjerulf, Halfdan
- Kleffel, Arno
- Klein, Bruno Oscar
- Klemperer, Otto
- Knab, Armin
- Knapp, Immanuel Friedrich
- Koczalski, Raoul
- Koechlin, Charles
- Korbay, Francis Alexander
- Korngold, Erich Wolfgang
- Kosma, Joseph
- Kramer, A. Walter
- Kreutzer, Conradin
- Kreuz, Emil
- Kücken, Friedrich Wilhelm
- Kuhlau, Daniel Friedrich Rudolph
- Lachner, Franz Paul
- Lacombe, Louis
- LaForge, Frank
- Lahoz y Otal, Florencio
- Lalo, Édouard
- Lang, Josephine
- Lange-Müller, Peter Erasmus
- Lange, Gustav
- Lange, Gustav Fredrik
- Laserna, Blas de
- Lassen, Eduard
- Lassus, Rolande de
- Lavigne, Ernest
- Lawes, Henry
- Lawes, William
- Lawson, Peter W.F.
- Lazzari, Sylvio
- Lecocq, Charles
- Legrenzi, Giovanni
- Leguerney, Jacques
- Lehár, Franz
- Lehmann, Amelia
- Lehmann, Liza