L
- R. A. Lafferty (1914–2002)
- Geoffrey Landis (born 1955)
- David Langford (born 1953)
- Sterling E. Lanier (1927–2007)
- Justine Larbalestier, Magic or Madness
- Glen A. Larson (born 1937)
- Kurd Lasswitz (1848–1910)
- Keith Laumer (1925–1993)
- Stephen R. Lawhead (born 1950)
- Ursula K. Le Guin (born 1929)
- Gentry Lee (born 1942)
- Sharon Lee (born 1952)
- Stan Lee (born 1922)
- Tanith Lee (born 1947)
- Kimmo Lehtonen (born 1967)
- Fritz Leiber (1910–1992)
- Murray Leinster (1896–1975) (pseudonym of Will F. Jenkins)
- Stanisław Lem (1921–2006)
- Edward M. Lerner (born 1949)
- Doris Lessing (born 1919)
- Jonathan Lethem (born 1964)
- Paul Levinson (born 1947)
- Roger Levy
- C. S. Lewis (1898–1963)
- Shariann Lewitt (born 1954)
- Jacqueline Lichtenberg (born 1942)
- Brad Linaweaver (born 1952)
- Dénis Lindbohm (1927–2005)
- Liu Cixin (born 1963)
- John Uri Lloyd (1849–1936)
- Jack London (1876–1916)
- Barry B. Longyear (born 1942)
- Jean Lorrah (born 1938)
- H. P. Lovecraft (1890–1937)
- Archibald Low (1888–1956)
- Lois Lowry (born 1937)
- George Lucas (born 1944), Star Wars
- Lucian (120-after 180)
- Nicole Luiken (born 1971)
- Sergey Lukyanenko (born 1968)
- Sam Lundwall (born 1941)
- Duncan Lunan (born 1945)
- Richard A. Lupoff (born 1935)
Read more about this topic: List Of Science Fiction Authors