A
- Dafydd ab Hugh (born 1960)
- Alexander Abasheli (1884–1954)
- Edwin Abbott (1838–1926), Flatland
- Kōbō Abe (1924–1993)
- Robert Abernathy (1924–1990)
- Dan Abnett (born 1965)
- Forrest J Ackerman (1916–2008)
- Douglas Adams (1952–2001)
- Robert Adams (1932–1990)
- Jerry Ahern (born 1946)
- Humayun Ahmed (born 1948)
- Jim Aikin (born 1948)
- Alan Burt Akers (pseudonym of Kenneth Bulmer)
- Brian Aldiss (born 1925)
- David M. Alexander (born 1945)
- Lloyd Alexander (1924–2007)
- Roger MacBride Allen (born 1957)
- Hans Joachim Alpers (1943–2011)
- Steve Alten (born 1959)
- Genrich Altshuller (1926–1998)
- Kingsley Amis (1922–1995)
- Paul Rafaelovich Amnuél (born 1944)
- Kevin J. Anderson (born 1962)
- Poul Anderson (1926–2001)
- Christopher Andrews (born 1970)
- Patricia Anthony (born 1947)
- Piers Anthony (born 1934), Xanth
- Christopher Anvil (1925–2009) (pseudonym of Harry C. Crosby)
- K. A. Applegate (born 1956)
- E.L. Arch (1922–1988) (pseudonym of Rachel Cosgrove Payes)
- Eleanor Arnason (born 1942)
- Robert Arthur (1909–1969)
- Catherine Asaro (born 1955)
- Neal Asher (born 1961)
- Francis Leslie Ashton (born 1904)
- Isaac Asimov (1920–1992) (Russian: Айзек Азимов)
- Janet Asimov (born 1926)
- Nancy Asire (born 1945)
- Robert Asprin (1946–2008), Myth Adventures, Phule's Company
- A. A. Attanasio (born 1951)
- Margaret Atwood (born 1939)
- Ayerdhal (born 1959)
Read more about this topic: List Of Science Fiction Authors