- Mannone, John C. (fl. 2000s-2010s) (stories)
- See jcmannone.wordpress.com
- Mansell, Jill (fl. 1990s-2010s) (stories) (assoc.)
- See jillmansell.co.uk
- Manser, Martin (1952- ) (stories) (assoc.)
- See martinmanser.co.uk
- Mansfield, Peter (1942- ) (stories)
- See fancyclopedia.org/peter-mansfield
- Manso, Leo [born Leo Jacob Mansowitz] (1914-1993) (art)
- See www.nytimes.com/1993/02/09/arts/leo-manso-dies-collagist-painter-and-teacher-78.html
- Mansouri, S(hawn) H. (fl. 2010s) (stories)
- See shmansouriblog.wordpress.com
- Mantchev, Lisa (fl. 2000s-2010s) (stories)
- See en.wikipedia.org/wiki/Lisa_Mantchev
- Manteufel, M. B.; pseudonym (fl. 2010s) (stories)
- See www.smashwords.com/profile/view/mbmanteufel
- Mantley, John (Truman) (1920-2003) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/mantley_john
- Manuel, Derek (fl. 2010s) (stories) (assoc.)
- See www.dmthewriter.com
- Manukyan, Alexandra (fl. 1990s-2010s) (art)
- See www.alexandramanukyan.com
- Manusos, Lyndsie (fl. 2010s) (stories)
- See lyndsiekay.wordpress.com
- Manvell, (Arnold) Roger (1909-1987) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/manvell_roger
- Manyukhin, Vladimir (fl. 2010s) (art)
- See mvn78.artstation.com
- Manzetti, Alessandro (fl. 2010s) (stories)
- See www.alessandromanzetti.net
- Manzieri, Maurizio (fl. 1990s-2010s) (stories) (art) (assoc.)
- See www.manzieri.com
- Mar, Valeria Rodríguez (fl. 2010s) (stories)
- See valeriarodriguezmar.blogspot.co.uk
- Marbais, Amanda (fl. 2010s) (stories)
- See www.joylandmagazine.com/authors/amanda-marbais
- Marchand, Joy (fl. 2000s) (stories)
- See www.joymarchand.com
- Marchand, Richard (fl. 2000s) (art)
- See richardmarchand.tumblr.com
- Marchese, Anthony (fl. 2010s) (stories)
- See alphaverse.blogspot.co.uk
- Marchetti, Lou(is J.) (1920-1992) (art)
- See loumarchetti.com
- Marcinek, Jaroslaw (fl. 2010s) (art)
- See yar0.deviantart.com
- Marco, John (fl. 1990s-2010s) (stories) (assoc.)
- See en.wikipedia.org/wiki/John_Marco
- Marconette, Walter E. (fl. 1930s-1950s) (stories)
- See fancyclopedia.wikidot.com/walter-e-marconette
- Marcus, Daniel (L.) (fl. 1990s-2010s) (stories)
- See en.wikipedia.org/wiki/Daniel_Marcus
- Marcus, Daryl (fl. 2010s) (stories)
- See darylmarcus.wordpress.com
- Marek, Kurt W(ilhelm) (1915-1972) (stories)
- See en.wikipedia.org/wiki/C._W._Ceram
- Margroff, Robert E(rvien) (1930-2015) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/margroff_robert_e
- Maria, Theresa Mahella (fl. 2010s) (art)
- See unlaceddreams.yolasite.com
- Maric, Karen (1970s- ) (stories)
- See karenmaric.com
- Mariella, [Dr.] Raymond Peel (, Sr.) (1919-2010) (stories)
- See file770.com/?p=4030
- Marietta, Becky (fl. 2010s) (stories)
- See thebeckymarietta.blogspot.co.uk
- Marillier, Juliet (1948- ) (stories) (assoc.)
- See en.wikipedia.org/wiki/Juliet_Marillier
- Marin, Augusto (1921-2011) (art)
- See articles.philly.com/2011-04-15/news/29421448_1_painter-lung-infection-murals
- Marín, Rafael [i.e., Rafael Marín Trechera] (1959- ) (stories)
- See en.wikipedia.org/wiki/Rafael_Mar%C3%ADn
- Mariner, Scott; pseudonym of C. M. Kornbluth (1923-1958) & Frederik Pohl (1919-2013) (stories)
- See www.sf-encyclopedia.com/entry/mariner_scott
- Marino, Andy (fl. 2000s-2010s) (stories)
- See andy-marino.com
- Marion, Elizabeth [i.e., Dora Elizabeth Marion Saunders] (1916-1989) (stories)
- Born in Washington state.
- Marius, Soare ({c}1979- ) (art)
- See www.runner44.deviantart.com
- Mark, Jan(et Marjorie) (1943-2006) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/mark_jan
- Markham, (Charles) Edwin (Anson) (1852-1940) (stories)
- See en.wikipedia.org/wiki/Edwin_Markham
- Markotin, Dimitri (fl. 2010s) (stories)
- See www.steamypunk.net/authors/dimitri_markotin/
- Markov, Georgi ({c}1980- ) (art)
- See hofarts.deviantart.com
- Markov, Haralambi (fl. 2010s) (stories)
- See haralambimarkov.com
- Marks, C(hris) S. (fl. 2010s) (stories) (assoc.)
- See www.csmarks.com
- Marley, Louise (née Campbell) (1952- ) (stories) (assoc.)
- See www.louisemarley.com
- Marlon, Brandon (fl. 2010s) (stories)
- See www.brandonmarlon.com
- Marlow, Gregory (fl. 2010s) (stories)
- See www.gregmarlow.com
- Marlow, Max; joint pseudonym of Diana Mary Bachmann (1950- ) & Christopher Nicole (1930- ) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/marlow_max
- Marlowe, Spike (fl. 2010s) (stories)
- See spikemarlowe.wordpress.com
- Marlowe, Stephen [born Milton Lesser] (1928-2008) (stories)
- See en.wikipedia.org/wiki/Stephen_Marlowe
- Marmell, Ari (1974- ) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/marmell_ari
- Marmor, Arnold (1927-1988) (stories)
- Born and died in New York City.
- Marmur, Jacland (1901-1970) (stories)
- Author and explorer. Born in Sosnowiec, Poland; came to the United States in 1918; died in San Rafael, California (?).
- Maroon, Everett (fl. 2010s) (stories)
- See transplantportation.com
- Marquez, R. (fl. 2010s) (stories)
- See www.r-marquez.com
- Marquitz, Tim (fl. 2010s) (stories) (assoc.)
- See www.tmarquitz.com
- Marr, Melissa (1972- ) (stories) (assoc.)
- See en.wikipedia.org/wiki/Melissa_Marr
- Marriott, (Norman) Ronald (1922-1972) (stories) (assoc.)
- See www.imdb.com/name/nm0550198/
- Marryat, [Captain] Frederick (1792-1848) (stories)
- Born in Westminster; went to sea at 14; author of novels for adults and children.
- Mars, Alastair (Campbell Gillespie) (1915-1985) (stories) (assoc.)
- See en.wikipedia.org/wiki/Alastair_Mars
- Mars, Chris(topher Edward) (1961- ) (stories) (art) (assoc.)
- See en.wikipedia.org/wiki/Chris_Mars
- Marsh, Howard R(oland) (1893-1974) (stories)
- Explorer, adventurer. Not to be confused with the musical actor of the same name (d. 1969).
- Marsh, Richard; pseudonym of Richard B. Heldmann (1857-1915) (stories) (assoc.)
- See en.wikipedia.org/wiki/Richard_Marsh_(author)
- Marsh, Richard (fl. 1970s-2010s) (stories)
- See richardmarshauthor.wordpress.com
- Marsh, Willard (N.) (1922-1970) (stories)
- See www.lib.uiowa.edu/scua/msc/tomsc800/msc794/msc794.html
- Marshack, Alexander (1918-2004) (stories) (assoc.)
- See en.wikipedia.org/wiki/Alexander_Marshack
- Marshak, Sondra (1940?- ) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/marshak_sondra
- Marshall, Alex; pseudonym of Jesse Bullington (fl. 2000s-2010s) (stories)
- See www.hachettebookgroup.com/authors/alex-marshall/
- Marshall, Denny E. (fl. 1990s-2010s) (stories) (art)
- See www.dennymarshall.com
- Marshall, Edison (Tesla) (1894-1967) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/marshall_edison
- Marshall, Helen (fl. 2000s-2010s) (stories) (assoc.)
- See www.helen-marshall.com
- Marshall, Kirk (fl. 2010s) (stories)
- See fun-with-kites.livejournal.com
- Marson, Richard ({c}1976- ) (stories)
- See en.wikipedia.org/wiki/Richard_Marson
- Mårtensson, Bertil (1945-2018) (stories)
- See en.wikipedia.org/wiki/Bertil_Mårtensson
- Martin, Al(bert Harry) (1895-1971) (stories)
- Born in Wisconsin; died in Los Angeles.
- Martin, Andrew (1962- ) (stories) (assoc.)
- See bearalley.blogspot.co.uk/2013/03/andrew-martin-cover-gallery.html
- Martin, Carrie (fl. 1990s-2010s) (stories)
- See carriemartin.ca
- Martin, Charles M(orris) Chuck (1891-1954) (stories)
- Some stories under this byline written by Charles S. Strong.
- Martin, Chester (Carlos) (1924-2013) (art)
- See www.pulpartists.com/Martin.html
- Martin, Cody (1987- ) (stories)
- See secretworldchronicle.com/about/author-cody-martin/
- Martin, David (fl. 2010s) (stories)
- See www.smashwords.com/profile/view/davidcmartin
- Martin, David Ralph (1935-2007) (stories)
- See en.wikipedia.org/wiki/Dave_Martin_(screenwriter)
- Martin, Don (1931-2000) (art)
- See en.wikipedia.org/wiki/Don_Martin_(cartoonist)
- Martin, George R(aymond) R(ichard) (1948- ) (stories) (assoc.)
- See en.wikipedia.org/wiki/George_R._R._Martin
- Martin, Graham Dunstan (1932- ) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/martin_graham_dunstan
- Martin, Ian (1912-1981) (stories)
- Born in Glasgow, Scotland; actor and playwright, especially for radio; died in New York City.
- Martin, Ian Kennedy (1936- ) (stories)
- Brother of Troy Kennedy Martin (1932-2009).
- Martin, J(ohn) P(ercival) (1879-1966) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/martin_j_p
- Martin, John Stuart (1900-1977) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/martin_john_s
- Martin, Marcia (fl. 1970s-1990s) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/martin_marcia
- Martin, Reginald Alec (1908-1971) (stories)
- See www.reginaldalecmartin.co.uk
- Martin, Robin (fl. 2000s) (stories)
- See www.thesteampunkempire.com/profile/RobinMartin
- Martin, Stuart [i.e., Allan Stewart Martin] (1881-1947) (stories)
- Born in Kilmarnock, Scotland; died in Richmond, Surrey; author and journalist.
- Martin, Terry (fl. 2000s-2010s) (stories)
- See www.terrymartin.me.uk
- Martin, Thomas Hector (1913-1985) (stories)
- Cartoonist and commercial artist turned novelist and short story writer.
- Martin, Watts (fl. 1990s-2010s) (stories) (assoc.)
- See en.wikifur.com/wiki/Watts_Martin
- Martine, Arkady (fl. 2010s) (stories) (assoc.)
- See arkadymartine.wordpress.com
- Martineck, Michael J. (fl. 2000s-2010s) (stories)
- See michaelmartineck.blogspot.co.uk
- Martinez, Christian K. (fl. 2010s) (stories)
- See dayswithaknight.com/about-the-author
- Martinez, Michael J. (fl. 2010s) (stories)
- See michaeljmartinez.net