- Martínez, Rodolfo (1965- ) (stories)
- See es.wikipedia.org/wiki/Rodolfo_Mart%C3%ADnez
- Martins, Márcio (fl. 2010s) (stories) (assoc.)
- See www.behance.net/MarcioM
- Martinson, Harry (Edmund) (1904-1978) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/martinson_harry
- Martland, Guy T. (fl. 1990s-2010s) (stories)
- See www.guytmartland.co.uk
- Marttila, Melanie (fl. 2010s) (stories)
- See melaniemarttila.ca
- Marusek, David (1951- ) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/marusek_david
- Marzioli, Samuel (fl. 2010s) (stories)
- See marzioli.blogspot.co.uk
- Mascari, Mary (fl. 2010s) (stories)
- See marymascari.wordpress.com
- Masello, Robert (fl. 1970s-2010s) (stories) (assoc.)
- See www.robertmasello.com
- Mason, David [i.e., Samuel Mason] (1924-1974) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/mason_david
- Mason, Douglas R(ankine) (1918-2013) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/mason_douglas_r
- Mason, Elmer Brown (1877-1955) (stories)
- See pulpflakes.blogspot.com/2012/10/ElmerBMason.html
- Mason, Grace Sartwell [i.e., Grace Sartwell Mason Howes] (1876-1966) (stories)
- Born and died in McKean County, Pennsylvania.
- Mason, Gregory (1889-1968) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/mason_gregory
- Mason, Jamie (fl. 2000s-2010s) (stories)
- See www.jamie-mason.com
- Mason, Lisa (Susan) (1953- ) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/mason_lisa
- Mason, Rena (fl. 2010s) (stories) (assoc.)
- See www.renamasonwrites.com
- Mason, Robert C(averly) (1942- ) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/mason_robert_c
- Mason, (Francis) Van Wyck (1901-1978) (stories)
- Mystery writer. Born in Boston, Massachusetts; died in Bermuda.
- Mason-Black, Jennifer (fl. 2010s) (stories)
- See www.jennifermasonblack.com
- Massa, Kyle (fl. 2010s) (stories)
- See kyleamassa.com
- Massey, Christopher (1880-1964) (stories)
- Born in London; novelist and literary advisor to Sampson Low, Publishers.
- Massey, Claire (1981- ) (stories)
- See nightjarpress.weebly.com/claire-massey.html
- Massey, [Sir] Harrie (Stewart Wilson) (1908-1983) (stories)
- See en.wikipedia.org/wiki/Harrie_Massey
- Masson, David I(rvine) (1915-2007) (stories)
- See www.sf-encyclopedia.com/entry/masson_david_i
- Mastrantone, S. R. (fl. 2010s) (stories)
- See thewrittenabsurd.blogspot.co.uk
- Masud, Naiyer (1936-2017) (stories) (assoc.)
- See en.wikipedia.org/wiki/Naiyer_Masud
- Masur, Harold Q. (1909-2005) (stories)
- See en.wikipedia.org/wiki/Harold_Q._Masur
- Matei, Liviu (fl. 2010s) (art)
- See liviumatei.carbonmade.com
- Mather, Victoria (fl. 2010s) (stories) (assoc.)
- See vickymather.co.uk
- Mathes, Steven (fl. 2000s-2010s) (stories)
- See stevenmathes.com
- Matheson, Michael (fl. 2010s) (stories)
- See michaelmatheson.wordpress.com
- Matheson, Richard (Burton) (1926-2013) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/matheson_richard
- Matheson, Richard Christian (1953- ) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/matheson_richard_christian
- Mathijsen, Django (fl. 2010s) (stories)
- See www.djangomathijsen.nl
- Mathison, Volney G. (1897-1965) (stories)
- See www.sf-encyclopedia.com/entry/mathison_volney_g
- Matsuoka, Yoko (fl. 2010s) (stories) (art) (assoc.)
- See www.m-y-designs.com
- Matsuura, Thersa (fl. 2010s) (stories)
- See www.thersamatsuura.com
- Matteson, H(erman) H(oward) (1876-1951) (stories)
- Author, ships surgeon, surgeon to Central American explorers and inmates in federal penitentaries; radio broadcaster. Born in Grundy County, Illinois; lived in Los Angeles, California.
- Matthews, (James) Brander (1852-1929) (stories)
- See en.wikipedia.org/wiki/Brander_Matthews
- Matthews, Jason (fl. 2010s) (stories)
- See pages.simonandschuster.com/redsparrow/meetjason
- Matthews, Patricia (Anne Klein, née Ernst) (1927-2006) (stories)
- See en.wikipedia.org/wiki/Patricia_Matthews
- Matthey, Cécile (1973- ) (art)
- See www.caeciliana.ch
- Mattila, D(eborah) L. (fl. 2010s) (stories)
- See www.pw.org/content/deborah_l_mattila
- Maughan, Tim (fl. 2010s) (stories) (assoc.)
- See timmaughanbooks.com
- Maupassant, (Henri René Albert) Guy de (1850-1893) (stories)
- See en.wikipedia.org/wiki/Guy_de_Maupassant
- Mauro, Laura (fl. 2010s) (stories)
- See crunchyblanket.wordpress.com
- Mavor, Elinor ({c}1936- ) (stories) (art)
- See en.wikipedia.org/wiki/Elinor_Mavor
- Mavor, James W(att), Jr. (1923-2008) (stories) (assoc.)
- See www.whoi.edu/main/obituaries/archive?tid=3622&cid=15786
- Mawhinney, Pete (fl. 2010s) (stories)
- See www.bookofpete.com/about
- Maxon, P(ercy) B(urden) (1887-1941) (stories)
- Born in New Brunswick, Canada; died in Detroit; a reporter.
- Maxwell, Ann (Elizabeth Lowell) (1944- ) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/maxwell_ann
- Maxwell, William (Keepers, Jr.) (1908-2000) (stories) (assoc.)
- See en.wikipedia.org/wiki/William_Keepers_Maxwell_Jr.
- May, Edna [i.e., Edna May Pettie] (1878-1948) (stories)
- See en.wikipedia.org/wiki/Edna_May
- May, Julian (Clare) [i.e., Julian Judy May Dikty] (1931-2017) (stories) (art) (assoc.)
- See www.sf-encyclopedia.com/entry/may_julian
- May, Kim (fl. 2010s) (stories)
- See ninjakeyboard.blogspot.co.uk
- Mayakovsky, Vladimir (Vladimirovich) (1893-1930) (stories)
- See www.sf-encyclopedia.com/entry/mayakovsky_vladimir
- Mayan, Earl Eugene (1916-2009) (stories) (art)
- See pulpartists.com/Mayan.html
- Mayer, Douglas W. F. (1919-1976) (stories)
- See fancyclopedia.wikidot.com/douglas-w-f-mayer
- Mayerik, Val (1950- ) (art)
- See en.wikipedia.org/wiki/Val_Mayerik
- Mayers, Dan E. (1922-2014) (stories)
- See www.shakuhachi.com/LL-Mayers.html
- Mayhar, Ardath (Frances Hurst) (1930-2012) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/mayhar_ardath
- Mayr, Dallas William (1946-2018) (stories)
- See en.wikipedia.org/wiki/Jack_Ketchum
- Mayr, Suzette (1967- ) (stories)
- See www.sf-encyclopedia.com/entry/mayr_suzette
- Maysi, Kadra (1890-1969) (stories)
- See tellersofweirdtales.blogspot.com/2012/03/kadra-maysi-1890-1969.html
- Mazur, Carly Janine (fl. 2010s) (stories) (art) (assoc.)
- See carlyjanine.com
- McAbee, K. G. (fl. 1990s-2010s) (stories)
- See kgmcabee.blogspot.co.uk
- McAdams, T. S. (fl. 2010s) (stories)
- See www.beneath-ceaseless-skies.com/authors/t-s-mcadams
- McAfee, David (Gregory) (1989- ) (stories) (assoc.)
- See en.wikipedia.org/wiki/David_G._McAfee
- McAllister, Angus (1943- ) (stories) (assoc.)
- See www.fantasticfiction.com/m/angus-mcallister/
- McAllister, Bruce (Hugh) (1946- ) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/mcallister_bruce
- McArthur, Maxine (1962- ) (stories)
- See www.sf-encyclopedia.com/entry/mcarthur_maxine
- McAuley, Paul J. (1955- ) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/mcauley_paul_j
- McAulty, Todd (fl. 2000s-2010s) (stories)
- See www.hauntedstars.com
- McAusland, William (fl. 2000s-2010s) (art)
- See www.mcauslandstudios.com/artist.htm
- McBain, Alison (fl. 2010s) (stories)
- See www.alisonmcbain.com
- McBrayer, Sasha Janel (fl. 2010s) (stories)
- See storybysasha.blogspot.co.uk
- McBreen, Brendan (fl. 2000s-2010s) (stories)
- See www.imagineauburn.com/poetry/brendan.htm
- McBride, Lish (fl. 2010s) (stories)
- See en.wikipedia.org/wiki/Lish_McBride
- McBride, Tracie (fl. 2000s-2010s) (stories)
- See traciemcbridewriter.wordpress.com
- McCabe, (Christopher) John (1967- ) (stories)
- Geneticist living in Birmingham.
- McCabe, Joseph (1972- ) (stories)
- See en.wikipedia.org/wiki/Joseph_McCabe_(editor)
- McCaffrey, Anne (Inez) (1926-2011) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/mccaffrey_anne
- McCaffrey, Gigi (fl. 2010s) (stories) (assoc.)
- Daughter of Anne McCaffrey.
- McCaffrey, Todd [born Todd Johnson] (1956- ) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/mccaffrey_todd
- McCain, Zach (fl. 2000s-2010s) (art)
- See www.zachmccain.com
- McCall, Becca (fl. 2010s) (art)
- See punkyourself.wordpress.com
- McCalmont, Jonathan (fl. 2010s) (stories)
- See ruthlessculture.com
- McCann, Edson; pseudonym of Lester del Rey (1915-1993) & Frederik Pohl (1919-2013) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/mccann_edson
- McCann, Gerald (Patrick) (1916-1995) (art)
- See pulpartists.com/McCannG.html
- McCarron, Meghan (fl. 2000s-2010s) (stories)
- See www.tor.com/members/Meghan_McCarron
- McCarry, Sarah (fl. 2010s) (stories)
- See www.therejectionist.com
- McCarten, Anthony (1961- ) (stories) (assoc.)
- See en.wikipedia.org/wiki/Anthony_McCarten
- McCarter, Robert J. (fl. 2010s) (stories)
- See robertjmccarter.com/about-robert
- McCarthy, Cormac (1933- ) (stories) (assoc.)
- See en.wikipedia.org/wiki/Cormac_McCarthy
- McCarthy, Mary (Therese) (1912-1989) (stories) (assoc.)
- Born in Seattle.
- McCarthy, Sean Padraic (fl. 2000s-2010s) (stories)
- See www.transmundanepress.com/sean-padraic-mccarthy.html
- McCarthy, T. C. (fl. 2010s) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/mccarthy_t_c
- McCarthy, Wil(liam Terence) (1966- ) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/mccarthy_wil
- McCartney, Paul (1942- ) (stories) (assoc.)
- See en.wikipedia.org/wiki/Paul_McCartney
- McCarty, Edward Clayton (Jr.) (1901-1986) (stories)
- Born in Louisville, Kentucky; died in Alpine, Texas, where he was chairman of the Theatre of the Big Bend.
- McCauley, Adam (fl. 2000s) (stories)
- See adammccauley.com