- Marshall, Edison (Tesla) (1894-1967) (stories)
- See www.sf-encyclopedia.com/entry/marshall_edison
- Marshall, Joseph R. (fl. 1950s-1960s) (stories)
- Reporter, magazine writer and editor; in public-relations.
- Marston, William Moulton (1893-1947) (stories)
- See en.wikipedia.org/wiki/William_Moulton_Marston
- Martin, A(rchibald) E(dward) (1885-1955) (stories)
- Born in Adelaide, Australia; traveled widely and toured Europe, working on fairgrounds; bought and showed documentary films; ran a travel agency.
- Martin, Al(bert Harry) (1895-1971) (stories)
- Born in Wisconsin; died in Los Angeles.
- Martin, Andrew (1962- ) (stories)
- See bearalley.blogspot.co.uk/2013/03/andrew-martin-cover-gallery.html
- Martin, Arthur Lewis (1902-1981) (stories)
- See bearalley.blogspot.co.uk/2017/05/brian-worthington-stuart-part-1.html
- Martin, Charles M(orris) Chuck (1891-1954) (stories)
- Some stories under this byline written by Charles S. Strong.
- Martin, Ian (1912-1981) (stories)
- Born in Glasgow, Scotland; actor and playwright, especially for radio; died in New York City.
- Martin, Neil (1885-1963) (stories)
- See pulpflakes.blogspot.co.uk/2015/07/pulp-reprints-collected-stories-of-sea.html
- Martin, Nell (Columbia Boyer) (1890-1968) (stories)
- Born Nellie Columbia Boyer in Illinois; later she was Nell Columbia Boyer Martin and then Nell Columbia Boyer Martin Dickinson, widow of (Ashley) Weed Dickinson.
- Martin, Nicolas (1980- ) (art)
- See www.theartofnicolasmartin.com
- Martin, Robert (Lee) (1908-1976) (stories)
- See www.mysteryfile.com/RMartin/Pronzini.html
- Martin, Stuart [i.e., Allan Stewart Martin] (1881-1947) (stories) (art)
- Born in Kilmarnock, Scotland; died in Richmond, Surrey; author and journalist.
- Martin, Thomas Hector (1913-1985) (stories)
- Cartoonist and commercial artist turned novelist and short story writer.
- Martyn, Frederic (fl. 1900s-1920s) (stories)
- Spent five years (1889-1894) in the French Foreign Legion; did 18 months at hard labor in an English prison for embezzlement; no birth/death dates found.
- Martyn, Wyndham; pseudonym of William Henry Martin Hosken (1874-1963) (stories)
- See bearalley.blogspot.co.uk/2007/07/wyndham-martyn-biographical-notes.html
- Martz, Matt (fl. 2010s) (stories) (assoc.)
- See www.crookedlanebooks.com
- Marwood, Alex (fl. 2010s) (stories) (assoc.)
- See www.alexmarwood.com
- Mary of Teck [i.e., Victoria Mary Augusta Louise Olga Pauline Claudine Agnes] (1867-1953) (stories) (assoc.)
- See en.wikipedia.org/wiki/Mary_of_Teck
- Maschwitz, (Albert) Eric (1901-1969) (stories)
- Born in Birmingham; educated at Cambridge; Director of Variety for the BBC; playwright.
- Masero, Tony (fl. 1970s-2010s) (stories) (art)
- See www.artnillustration.com
- Maslin, Janet (R.) (1949- ) (stories) (assoc.)
- See en.wikipedia.org/wiki/Janet_Maslin
- Mason, Elmer Brown (1877-1955) (stories)
- See pulpflakes.blogspot.com/2012/10/ElmerBMason.html
- Mason, Michael Henry (1900-1982) (stories)
- Born in Carnbee, Fife; educated at Eton and Sandhurst; landed proprietor and explorer.
- Mason, (Francis) Van Wyck (1901-1978) (stories) (assoc.)
- Mystery writer. Born in Boston, Massachusetts; died in Bermuda.
- Massey, Sujata (Banerjee) (1964- ) (stories) (assoc.)
- Born in England; was feature reporter for Baltimore Sun; also lived in Japan before returning to Baltimore.
- Masson, Thomas L(ansing) (1866-1934) (stories)
- See en.wikipedia.org/wiki/Thomas_Lansing_Masson
- Masterman, Walter S(idney) (1876-1946) (stories)
- See www.sf-encyclopedia.com/entry/masterman_walter_s
- Masters, John (1914-1983) (stories)
- See en.wikipedia.org/wiki/John_Masters
- Masters, Priscilla (1952- ) (stories) (assoc.)
- Born in Halifax, Yorkshire, the third of seven multiracial children adopted by an orthopedic surgeon and his wife; brought up in Wales; trained as a nurse in Birmingham.
- Masur, Harold Q. (1909-2005) (stories) (assoc.)
- See en.wikipedia.org/wiki/Harold_Q._Masur
- Mata Hari [i.e., Margaretha Geertruida MacLeod (née Zelle)] (1876-1917) (stories) (assoc.)
- See en.wikipedia.org/wiki/Mata_Hari
- Mather, Berkely; pseudonym of John Evan Weston Davies (1909-1996) (stories)
- See en.wikipedia.org/wiki/Berkely_Mather
- Matheson, Richard (Burton) (1926-2013) (stories)
- See www.sf-encyclopedia.com/entry/matheson_richard
- Mathews, Frances Aymar (1865-1925) (stories)
- Born in New York City.
- Mathison, Volney G. (1897-1965) (stories)
- See www.sf-encyclopedia.com/entry/mathison_volney_g
- Matson, Norman (Haghejm) (1893-1965) (stories)
- See www.sf-encyclopedia.com/entry/matson_norman
- Matter, John (1883-1949) (stories)
- Indiana author; died in Illinois.
- 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, Patricia (Anne Klein, née Ernst) (1927-2006) (stories) (assoc.)
- See en.wikipedia.org/wiki/Patricia_Matthews
- Maugham, Robin [i.e., Robert Cecil Romer Maugham, 2nd Viscount Maugham] (1916-1981) (stories)
- See en.wikipedia.org/wiki/Robin_Maugham
- Maupassant, (Henri René Albert) Guy de (1850-1893) (stories) (assoc.)
- See en.wikipedia.org/wiki/Guy_de_Maupassant
- Maurice, Arthur B(artlett) (1873-1946) (stories)
- Born in Rahway, New Jersey; educated at Princeton University; editor of The Bookman 1899-1916; newspaper editor.
- Maury, Magruder (Gordon) (1878-1948) (stories)
- Journalist. Born in Philadelphia, Pennsylvania; died in Bethesda, Maryland.
- Mavity, Nancy Barr (1890-1959) (stories)
- Born in Lawrenceville, Illinois. Crime journalist for California newspaper; living in Oakland in the 1930s.
- Mawdsley Graham, Winston [born Winston Grime] (1908-2003) (stories)
- Born Winston Grime (no middle name). He changed his name by deed poll on 2 June 1947, adopting the surname of Mawsely Graham at that time.
- Maxon, Rex (Hayden) (1892-1973) (stories)
- See pulpartists.com/Maxon.html
- Maxwell, Ann (Elizabeth Lowell) (1944- ) (stories)
- See www.sf-encyclopedia.com/entry/maxwell_ann
- Maxwell, Edith M. (fl. 2010s) (stories)
- See edithmaxwell.com
- Maxwell, William (Keepers, Jr.) (1908-2000) (stories)
- See en.wikipedia.org/wiki/William_Keepers_Maxwell_Jr.
- May, Susan ({c}1960- ) (stories) (assoc.)
- See susanmaywordadventures.blogspot.com.au
- Mayan, Earl Eugene (1916-2009) (stories) (art)
- See pulpartists.com/Mayan.html
- Mayer, Bob [i.e., Robert Mayer] (1959- ) (stories)
- See www.sf-encyclopedia.com/entry/mayer_bob
- Mayer, Robert (1939- ) (stories)
- See www.sf-encyclopedia.com/entry/mayer_robert
- Mayhar, Ardath (Frances Hurst) (1930-2012) (stories)
- See www.sf-encyclopedia.com/entry/mayhar_ardath
- Mayhew, Henry (1812-1887) (stories)
- See en.wikipedia.org/wiki/Henry_Mayhew
- Maynard, Lawrance M(arion) (1899-1982) (stories)
- Born in Kansas City, Missouri; died in Hawaii.
- Mayr, Dallas William (1946-2018) (stories)
- See en.wikipedia.org/wiki/Jack_Ketchum
- Maysi, Kadra (1890-1969) (stories)
- See tellersofweirdtales.blogspot.com/2012/03/kadra-maysi-1890-1969.html
- Mazel, Henry F. (1945- ) (stories)
- Filmmaker, playwright, screenwriter, and therapist.
- Mazuk, Harley (1948- ) (stories)
- See www.harleymazuk.com/about-harley.html
- McAbee, K. G. (fl. 1990s-2010s) (stories)
- See kgmcabee.blogspot.co.uk
- McAleer, Andrew (1958- ) (stories)
- Son of John (Joseph) McAleeer.
- McAleer, John (Joseph) (1923-2003) (stories)
- Father of Andrew McAleer.
- McArdle, Jay [i.e., James Nivison McArdle] (1899-1960) (art)
- See pulpartists.com/McArdle.html
- McAuley, Paul J. (1955- ) (stories)
- See www.sf-encyclopedia.com/entry/mcauley_paul_j
- McBlair, Robert (fl. 1910s-1940s) (stories)
- Perhaps the McBlair from New York (1888-1976).
- McBride, Matthew J. (fl. 2010s) (stories) (assoc.)
- See igotpulp.blogspot.co.uk
- McCafferty, (Barbara) Taylor (1946- ) (stories) (assoc.)
- See www.encyclopedia.com/arts/educational-magazines/mccafferty-barbara-taylor-1946
- McCaig, Robert J(esse) (1907-1982) (stories)
- See archiveswest.orbiscascade.org/ark:/80444/xv72848
- McCardell, Roy L(arcom) (1870-1961) (stories)
- See www.sf-encyclopedia.com/entry/mccardell_roy_l
- McCarry, (Albert) Charles (Jr.) (1930-2019) (stories) (assoc.)
- See en.wikipedia.org/wiki/Charles_McCarry
- McCarthy, Cormac (1933- ) (stories) (assoc.)
- See en.wikipedia.org/wiki/Cormac_McCarthy
- McCauley, Harold W(illiam) (1913-1977) (art)
- See pulpartists.com/McCauley.html
- McCauley, Terrence P. (fl. 2010s) (stories)
- See terrencemccauley.blogspot.co.uk
- McClary, Thomas Calvert (1909-1972) (stories)
- See www.sf-encyclopedia.com/entry/mcclary_thomas_calvert
- McClintick, Malcolm (1942- ) (stories)
- Former public defender living in Indianapolis.
- McCloy, Helen (Worrell Clarkson) (1904-1992) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/mccloy_helen
- McClusky, Thorp (1906-1975) (stories)
- Free-lance writer, former editor of Motor magazine; also wrote juveniles and a book on chiropractics. Studied music at Syracuse University. During the 1960s he lived in Atlantic Highlands, New Jersey. Probably died in Eatontown, Monmouth, New Jersey.
- McComas, J(esse) Francis (1911-1978) (stories)
- See www.sf-encyclopedia.com/entry/mccomas_j_francis
- McCormick, William Burton (fl. 2010s) (stories)
- See www.goodreads.com/author/show/5447401.William_Burton_McCormick
- McCrary, Mike (fl. 2010s) (stories)
- See www.goodreads.com/author/show/7020789.Mike_McCrary
- McCrumb, Sharyn (Elaine Atwood) (1948- ) (stories)
- See www.sf-encyclopedia.com/entry/mccrumb_sharyn
- McCulley, Johnston (1883-1958) (stories) (assoc.)
- Prolific pulp writer, mystery writer, screenwriter, creator and author of Zorro novels. Born in Ottawa, Illinois; died in California.
- McDaniel, David (Edward) (1939-1977) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/mcdaniel_david
- McDermid, Finlay (Angus) (1905-1987) (stories)
- Born in California; graduate of Stanford University; movie story editor and TV script writer.
- McDermott, H. Charles; pseudonym (fl. 1930s-1940s) (stories)
- Wrote detective and western stories while serving 10-20 for robbery.
- McDonald, Craig (fl. 2000s-2010s) (stories) (assoc.)
- See www.craigmcdonaldbooks.com
- McDonough, Yona Zeldis (1957- ) (stories)
- See www.encyclopedia.com/arts/educational-magazines/mcdonough-yona-zeldis-1957
- McDowall, Iain (1952- ) (stories)
- Born in Scotland and living in England; philosophy lecturer and computer specialist turned writer.
- McDowell, (Robert) Emmett (1914-1975) (stories)
- See desturmobed.blogspot.co.uk/2011/12/robert-emmett-mcdowell.html
- McFadden, Dennis (fl. 2010s) (stories)
- See ordinarypeopleextraordinarylives.edublogs.org/dennis-mcfadden
- McFadden, Edward J., III (fl. 1990s-2010s) (stories)
- See www.edwardmcfadden.com