| Adrien de La Fage | 1801 - 1862 | France | 4 |
| Olli-Pekka Laakkonen | 1961 - | Finland | 1 |
| Charles Labelle | 1849 - 1903 | Canada | 3 |
| Josef Labitzky | 1802 - 1881 | Czech Republic | 1 |
| Francisco Labler | 19th - century | Czech Republic ? | 1 |
| Bernard-Germain de Lacépède | 1756 - 1825 | France | 1 |
| Robert Lach | 1874 - 1958 | Austria | 1 |
| Hans Lachman | 1906 - 1990 | Germany | The Netherlands | 1 |
| Franz Lachner | 1803 - 1890 | Germany | 1 |
| Paul Lacombe | 1837 - 1927 | France | 1 |
| Christopher Lacy | 1956 - | United States of America, CA | 1 |
| Daniel Lagkhner | aft.1550 - aft.1607 | Slovenia | 1 |
| Francis Lai | 1932 - 2018 | France | 1 |
| Lori Laitman | 1955 - | United States of America, NY | 1 |
| Fernand Laloux | 1901 - 1970 | Belgium | Great Britain | 1 |
| Wim Laman | 1946 - | The Netherlands | 1 |
| José Angel Lamas | 1775 - 1814 | Venezuela | 3 |
| Johann Alois Lamb | c.1760 - 1820 | Czech Republic, Bohemia | 1 |
| Juan Lambert Caminal | 1884 - 1945 | Spain | 1 |
| Louis Lambillotte | 1796 - 1855 | Belgium | 1 |
| L. Lambinet | 19th - century | Belgium | 1 |
| Lancheri | 18th/19th - century | France (?) | 1 |
| Thierry Lancino | 1954 - | France | 1 |
| Cyril Lander | 1904 - 1989 | New Zealand | 1 |
| Giuseppe Landi | fl.1792 - 1801 | Italy | 1 |
| Wim Landré | 1874 - 1948 | The Netherlands | 1 |
| Fritz Lange | 1873 - 1933 | Austria | 1 |
| Daniël de Lange | 1841 - 1918 | The Netherlands | 1 |
| Huub de Lange | 1955 - | The Netherlands | 1 |
| Samuel de Lange jr. | 1840 - 1911 | The Netherlands | 1 |
| Jean Langlais | 1907 - 1991 | France | 2 |
| Honoré Langlé | 1741 - 1807 | Monaco | 1 |
| Pierre Lantier | 1910 - 1998 | France | 1 |
| Carlo Lapini | 1724 - 1802 | Italy | 1 |
| Roméo Larivière | 1880 - 1939 | Canada | 3 |
| Louisa Lasdun | 1956 - | Great Britain | Switzerland | 1 |
| Hannah Lash | 1981 - | United States of America | NY | 1 |
| Orlando di Lassus | 1532 - 1594 | Belgium / The Netherlands | 23 |
| Celestino da Laterina | 19th - century | Italy | 1 |
| Christian Latrobe | 1758 - 1836 | Great Britain, England | 1 |
| Heinz Lau | 1925 - 1975 | Germany | Poland | 1 |
| Anton Laube | 1718 - 1784 | Czech Republic | 1 |
| Anne Lauber | 1943 - | Switzerland | Canada | 1 |
| Joseph Laucher | 1737 - 1813 | Germany | 3 |
| Adolf Lauer von Münchhofen | 1796 - 1874 | Germany | 1 |
| Elisabeth Lauer-Larsen | 1932 - | United States of America, MA | 1 |
| Morten Lauridsen | 1943 - | United States of America, WA | 1 |
| Pierre Lauverjat | c.1565 - 1625 | France | 1 |
| Ljudevit Laušin | 1982 - | Croatia | 1 |
| Armando Lavalle García | 1924 - 1994 | Mexico | 1 |
| Alphonse Lavallée-Smith | 1873 - 1912 | Canada | 1 |
| Thomas LaVoy | 1990 - | United States of America | MI | 1 |
| Zenoby Lawryshyn | 1943 - 2017 | Ukrain | Canada | 1 |
| Malcolm Lawson | 1849 - 1918 | Great Britain, England | 1 |
| Francisco de Layolle | 1492 - c.1540 | Italy | 1 |
| Simo Lazarov | 1948 - | Bulgaria | 1 |
| Scipione Lazzarini | 1641 - aft.1675 | Italy | 1 |
| Rodrigo Leão | 1964 - | Portugal | 1 |
| Nicolai Lebedev | 1947 - 2000 | Russia | 1 |
| Benedict Lechler | 1594 - 1659 | Germany | 1 |
| Konrad Lechner | 1911 - 1989 | Germany | 1 |
| Leonard Lechner | 1553 - 1606 | Austria | 5 |
| Peter Wolfgang Lechner | 1717 - 1788 | Austria | 1 |
| Philip Ledger | 1937 - 2012 | Great Britain, England | 1 |
| Frédéric Ledroit | 1968 - | France | 1 |
| Franz Ledwinka | 1883 - 1972 | Austria | 1 |
| Rowland Lee | 1960 - | Great Britain | England | 1 |
| Hans Leenders | 1965 - | The Netherlands | 1 |
| Daryl Leeworthy | 1986 - | Great Britain | 1 |
| Giovanni Legrenzi | 1626 - 1690 | Italy | 1 |
| Liza Lehmann | 1862 - 1918 | Great Britain, England | 1 |
| Leonard Lehrman | 1949 - | United States of America, MO | 1 |
| Jón Leifs | 1899 - 1968 | Iceland | 1 |
| Roland Leistner-Mayer | 1945 - | Czech Republic | Germany | 1 |
| Josef Leiter | 1830 - 1887 | Austria | 1 |
| Ernst Ludwig Leitner | 1943 - | Austria | 1 |
| Karl Leitner | 1837 - 1904 | Germany | 1 |
| Alois Lejeal | 1840 - 1920 | France | 1 |
| Rex Lelacheur | 1910 - 1984 | Great Britain, England | Canada | 1 |
| Andrzej Lelen | 20th - century | Poland | 1 |
| Heinrich Lemacher | 1891 - 1966 | Germany | 1 |
| Aubert Lemeland | 1932 - 2010 | France | 1 |
| Joseph-Léopold Lemieux | 1908 - 1992 | Canada | 1 |
| Pietro Lenci | 1743 - 1806 | Italy | 1 |
| Kamillo Lendvay | 1928 - 2016 | Hungary | 1 |
| Charles Lenepveu | 1840 - 1910 | France | 2 |
| Nicholas Lens | 1957 - | Belgium | 1 |
| Daniel Lentz | 1942 - | United States of America, PA | 1 |
| Engelbert Lenz | 1910 - ? | Austria | 1 |
| Carlo Lenzi | 1735 - 1805 | Italy | 2 |
| Ruggiero Leoncavallo | 1858 - 1919 | Italy | 1 |
| Leone Leoni | c.1560 - 1627 | Italy | 1 |
| Kaiser Leopold I | 1640 - 1705 | Austria | 2 |
| Anatoly Lepin | 1907 - 1984 | Russia | 1 |
| Terje Lerstad | 1955 - | Norway | 2 |
| Charles Lesaffre | 1949 - | France | 1 |
| Antonio Lesbio | 1639 - 1709 | Portugal | 2 |
| François Lescot | c.1720 - c.1801 | France | 1 |
| Franciszek Lessel | c.1780 - 1838 | Poland | 2 |
| Jean-François Lesueur | 1760 - 1837 | France | 2 |
| Josep de Letamendi i de Manjarrés | 1828 - 1897 | Spain | 2 |
| Bruno Letort | 1963 - | France | 1 |
| Claude Léveillée | 1932 - 2011 | Canada | 1 |
| Charles Levens | 1689 - 1764 | France | 2 |
| Yuri Levitin | 1912 - 1993 | Ukraine | 1 |
| Frank Lewin | 1925 - 2008 | Germany | United States of America | 1 |
| Bernhard Lewkovitch | 1927 - | Denmark | 1 |
| Joseph Leybach | 1817 - 1891 | France | 1 |
| Antonin Lhoumeau | 1852 - 1920 | France | 1 |
| Davide Liani | 1921 - 2005 | Italy | 1 |
| Jean-Paul Liardet | 1939 - | Switzerland | 1 |
| Santiago Lichius | 1877 - 1973 | Germany | Argentina | 10 |
| Georg Lickl | 1769 - 1843 | Austria | 6 |
| Ingvar Lidholm | 1921 - 2017 | Sweden | 1 |
| Joseph Liebl | 1776 - 1838 | Germany (?) | 1 |
| Juan de Lienas | fl. 1617 - 1654 | Spain | Mexico | 1 |
| Otto Lies | 1869 - 1955 | The Netherlands | Germany | 1 |
| György Ligeti | 1923 - 2006 | Hungary | 2 |
| Lucas de Lil | 1963 - | Belgium | 2 |
| Fridolin Limbacher | 1914 - 1990 | Germany | 1 |
| Franz Limmer | 1808 - 1857 | Austria | 1 |
| Armand Limnander de Nieuwenhove | 1814 - 1892 | Belgium | 1 |
| Nils Lindberg | 1933 - 2022 | Sweden | 1 |
| Oskar Lindberg | 1887 - 1955 | Sweden | 1 |
| Tobias Lindh | 1976 - | Sweden | 1 |
| Jiří Ignác Linek | 1725 - 1791 | Czech Republic | 2 |
| Johann Lininger | 18th/19th - century | Czech Republic (?) | 1 |
| Jouko Linjama | 1934 - 2022 | Finland | 2 |
| William Linley | 1771 - 1835 | Great Britain, England | 1 |
| Jakob Linner | 18th/19th - century (?) | Germany (?) | 1 |
| Thaddäus Lipowsky | 1738 - 1767 | Germany | 1 |
| Alban Lipp | 1866 - 1903 | Germany | 3 |
| Guglielmo Lipparino | c.1580 - 1635 | Italy | 1 |
| Kurt Lissmann | 1902 - 1983 | Germany | 1 |
| Franz Liszt | 1811 - 1886 | Hungary | 1 |
| Giovanni Liverati | 1772 - 1846 | Italy | 1 |
| Ignacio Llaurado | 1887 - 1974 | Spain | 1 |
| Pere Joan Llonell | fl. 1775 - 1825 | Spain | 1 |
| George Lloyd | 1913 - 1998 | Great Britain, England | 1 |
| David de Lloyd | 1883 - 1948 | Great Britain, Wales | 1 |
| Andrew Lloyd Webber | 1948 - | Great Britain, England | 1 |
| Theodor Lobmiller | 1873 - 1955 | Germany | 2 |
| Alonso Lobo | c.1555 - 1617 | Spain | 5 |
| Duarte Lôbo | c.1565 - 1646 | Portugal | 4 |
| Emerico Lobo de Mesquita | 1746 - 1805 | Brazil | 3 |
| David Lockart | 1955 - | United States of America, WA | 1 |
| Dan Locklair | 1949 - | United States of America | 1 |
| Normand Lockwood | 1906 - 2002 | United States of America, NY | 1 |
| Nikolay Lodyzhensky | 1843 - 1916 | Russia | 1 |
| Theo Loevendie | 1930 - | The Netherlands | 1 |
| Cissie Loftus | 1876 - 1943 | Great Britain, Scotland | 1 |
| Dietrich Lohff | 1941 - 2016 | Germany | 1 |
| August Lohle | 1859 - 1919 | Germany | 1 |
| Alois Lohmiller | 1934 - 2019 | Germany | 1 |
| Johann Lohr | 1828 - 1892 | Hungary | 1 |
| Alexander Lokshin | 1920 - 1987 | Russia | 1 |
| Ruggero Lolini | 1932 - 2019 | Italy | 1 |
| Enrique Lombardi | 1922 - 2013 | Argentina | 1 |
| Luca Lombardi | 1945 - | Italy | 1 |
| Ruth Lomon | 1930 - 2017 | Canada | United States of America, MA | 1 |
| Achille Longo | 1900 - 1954 | Italy | 1 |
| Stijn van der Loo | 1963 - | The Netherlands | 1 |
| Karel Loos | 1724 - 1772 | Czech Republic | 1 |
| Fernando Lopes-Graça | 1906 - 1994 | Portugal | 1 |
| Antonio Lopez | 16th/17th - century | Portugal | 1 |
| Miquel Lopez | 1669 - 1723 | Spain | 1 |
| Sebastián Lopez de Velasco | 1584 - 1659 | Spain | 1 |
| Melchor Lopez Jimenez | 1760 - 1822 | Spain | 2 |
| Raimondo Lorenzini | c.1730 - 1806 | Italy | 1 |
| Erik Lotichius | 1929 - 2015 | The Netherlands | 1 |
| Antonio Lotti | c.1667 - 1740 | Italy | 4 |
| Alexandre Louet | 1753 - 1817 | France | 2 |
| Jonathan Lovenstein | 1952 - | United States of America, OH | 1 |
| Luis Lozano Virumbrales | 20th - century | Spain | 1 |
| Timothy Luby | 1946 - | United States of America, NY | 1 |
| Clarence Lucas | 1866 - 1947 | Canada | 1 |
| David Lucas | 20th - century | Great Britain, England | 1 |
| Leighton Lucas | 1903 - 1982 | Great Britain, England | 1 |
| Helen Lucas-Pyke | 1905 - 1954 | Great Britain, England | 1 |
| Andrea Lucchesi | 1741 - 1801 | Italy | 2 |
| Achille Lucidi | 1847 - 1901 | Italy | 1 |
| Wolfgang Luderitz | 1926 - 2012 | Germany | 1 |
| Nicholas Ludford | c.1485 - 1557 | Great Britain, England | 1 |
| Otto Luening | 1900 - 1996 | United States of America, WI | 1 |
| Jon Lugo | 1958 - | United States of America, CA | 1 |
| Enguerrand-Friedrich Luhl Dolgorukiy | 1975 - | France | 1 |
| Aloysius Luigi | 18th - century | Italy (?) | 1 |
| Zdenek Lukas | 1928 - 2007 | Czech Republic | 1 |
| Pawel Lukaszewski | 1968 - | Poland | 1 |
| Christopher Luke | 1972 - | Australia (?) | 1 |
| Jean-Baptiste Lully | 1632 - 1687 | Italy | France | 2 |
| Joaquín Luna | 19th - century | Mexico | 1 |
| Carl Lundell | 1859 - 1916 | Sweden | 1 |
| Torbjörn Lundquist | 1920 - 2000 | Sweden | 1 |
| Witold Lutoslawski | 1913 - 1994 | Poland | 1 |
| Alfred Lutz | 1952 - | Germany | 1 |
| Elisabeth Luytens | 1906 - 1983 | Great Britain, England | 2 |
| Albert Lynch | 1900 - 1976 | Australia | 1 |