- Kaiser, Robert Blair (1930- ) (stories)
- See en.wikipedia.org/wiki/Robert_Blair_Kaiser
- Kaldera, Raven B. (fl. 1990s-2000s) (stories) (assoc.)
- See www.ravenkaldera.org
- Kaledin, [Colonel] Victor K(onstantine Cecil Luke de Mordowtzeff) (1887-?) (stories)
- Born in Russia; lived in England and in the U.S., where he applied for citizenship; later (in 1956) living in Norway.
- Kalez, Jay J. (1895-1982) (stories) (assoc.)
- Writer. Born in Spokane, Washington.
- Kalin, Deborah (fl. 2000s-2010s) (stories)
- See www.deborahkalin.com
- Kalischer, Peter (1915-1991) (stories)
- See en.wikipedia.org/wiki/Peter_Kalischer
- Kallen, Kitty [born Katie Kallen] (1921-2016) (stories) (assoc.)
- See en.wikipedia.org/wiki/Kitty_Kallen
- Kalman, Maira (1949- ) (art)
- See en.wikipedia.org/wiki/Maira_Kalman
- Kalorkoti, Eleni (fl. 2010s) (art)
- See www.elenikalorkoti.com
- Kalpakian, Laura (Anne) (1945- ) (stories)
- See en.wikipedia.org/wiki/Laura_Kalpakian
- Kalteis, Dietrich (fl. 2010s) (stories) (art) (assoc.)
- See dietrichkalteis.blogspot.co.uk
- Kaltenborn, H(ans) V(on) (1878-1965) (stories)
- See en.wikipedia.org/wiki/H._V._Kaltenborn
- Kalu, Peter (fl. 1990s) (stories) (assoc.)
- Translator, glass collector and street busker turned poet, novelist, playwright and script writer; has a degree in law and further qualifications in software programming; living in Hulme, England.
- Kamarck, Lawrence (1927-2001) (stories)
- See www.sf-encyclopedia.com/entry/kamarck_lawrence
- Kamel, Babo (fl. 2010s) (stories)
- See rustandmoth.com/artists/babo-kamel
- Kamin, Nick; pseudonym of Robert J. Antonick (1939-2011) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/kamin_nick
- Kaminsky, Howard (1940-2017) (stories)
- See en.wikipedia.org/wiki/Howard_Kaminsky
- Kaminsky, Ilya (1977- ) (stories)
- See en.wikipedia.org/wiki/Ilya_Kaminsky
- Kammerud, Chris (fl. 2000s-2010s) (stories)
- See chriskammerud.com
- Kamp, Irene Kittle (1910-1985) (stories)
- See www.nytimes.com/1985/06/17/nyregion/irene-kittle-kamp-editor-who-wrote-for-stage-and-films.html
- Kamsika, Georgina (Rachael) (fl. 2010s) (stories)
- See en.wikipedia.org/wiki/Georgina_Kamsika
- Kamyshansky, Boris N. (fl. 1930s) (stories)
- Civil engineer. Born in Russia of a wealthy cossack family, led an adventurous early life. Father of Natalie B. Sokoloff.
- Kanakia, Rahul (1985- ) (stories)
- See blotter-paper.com
- Kanas, Nick, M.D. (fl. 2000s-2010s) (stories) (assoc.)
- See lppiweb.ucsf.edu/faculty.aspx?id=578
- Kandel, Aben (1897-1993) (stories)
- See en.wikipedia.org/wiki/Aben_Kandel
- Kandel, Michael (1941- ) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/kandel_michael
- Kane, Henry (J.) (1908-1988) (stories) (assoc.)
- See www.mulhollandbooks.com/2010/11/22/the-murders-in-memory-lane-remembering-henry-kane
- Kane, Joe (fl. 1980s-1990s) (stories)
- See en.wikipedia.org/wiki/Joe_Kane
- Kane, William R(eno) (1885-?) (stories)
- Born in Port Carbon, Pennsylvania; magazine and journal editor, including of The Editor from 1910.
- Kane, Wilson; house pseudonym (stories)
- See www.sf-encyclopedia.com/entry/kane_wilson
- Kang, Minsoo (1967- ) (stories)
- See en.wikipedia.org/wiki/Minsoo_Kang
- Kanin, Michael (1910-1993) (stories)
- See en.wikipedia.org/wiki/Michael_Kanin
- Kanke, Jennifer Schomburg (fl. 2000s-2010s) (stories)
- See www.jenniferschomburgkanke.com
- Kant, Hermann (1926-2016) (stories)
- See en.wikipedia.org/wiki/Hermann_Kant
- Kantner, Paul (1941-2016) (stories) (assoc.)
- See en.wikipedia.org/wiki/Paul_Kantner
- Kantner, (Timothy) Rob(in) (1952- ) (stories) (assoc.)
- Author of short stories, many featuring the series character in the listed books; living in Detroit area since 1972.
- Kantor, Loren (fl. 2000s-2010s) (stories) (assoc.)
- See woodcuttingfool.blogspot.co.uk
- Kantor, MacKinlay (1904-1977) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/kantor_mackinlay
- Kantor, Seth (1926-1993) (stories)
- Journalist and writer. Born in New York City; lived in Bethesda, Maryland.
- Kapetansky, Seymour (1919-2001) (stories)
- See variety.com/2001/scene/people-news/seymour-kapetansky-1117794271
- Kaplan, A. L. (fl. 2010s) (stories) (assoc.)
- See alkaplan.daportfolio.com
- Kaplan, Bruce Eric (1964- ) (art)
- See en.wikipedia.org/wiki/Bruce_Eric_Kaplan
- Kaplan, Hester (1959- ) (stories)
- See en.wikipedia.org/wiki/Hester_Kaplan
- Kaplan, Martha (fl. 2010s) (stories)
- See www.marthakaplanpoet.com
- Kapp, Colin (1928-2007) (stories) (art) (assoc.)
- See www.sf-encyclopedia.com/entry/kapp_colin
- Kapp, Edmond X(avier) (1890-1978) (art)
- See en.wikipedia.org/wiki/Edmond_Xavier_Kapp
- Kapp, Reginald O(tto) (1885-1966) (stories) (assoc.)
- See www.reginaldkapp.org/AboutROK/About_biography.htm
- Kappus, Franz Xaver (1883-1966) (stories)
- See en.wikipedia.org/wiki/Franz_Xaver_Kappus
- Karageorge, Penelope (1935- ) (stories)
- Newspaper and magazine writer.
- Karageorgevich, Alexis (1859-1920) (stories)
- See en.wikipedia.org/wiki/Prince_Alexis_Karageorgevich
- Karagiannis, George S. (1984- ) (stories) (art)
- See karagiannis-sci-fi.blogspot.co.uk
- Karakas, Mike [i.e., Michael George Karakas] (1911-1992) (stories)
- See en.wikipedia.org/wiki/Mike_Karakas
- Karanovic, Milos (1993- ) (stories) (assoc.)
- See www.plavidemon.com
- Karásek ze Lvovic, Jiří (1871-1951) (stories) (assoc.)
- See en.wikipedia.org/wiki/Ji%C5%99%C3%AD_Kar%C3%A1sek_ze_Lvovic
- Kardiner, Abram (1891-1981) (stories)
- Psychiatrist and author. Born in New York City; died in Easton, Connecticut.
- Kareska, Lane (fl. 2010s) (stories)
- See www.lanekareska.com
- Karig, Walter (1898-1956) (stories)
- See www.sf-encyclopedia.com/entry/karig_walter
- Karinthy, Ferenc (1921-1992) (stories)
- See en.wikipedia.org/wiki/Ferenc_Karinthy
- Kark, Austen (Steven) (1926-2002) (stories)
- Born in London; educated at Oxford; reporter for and then head of BBC World Service. Husband of Nina Bawden.
- Kark, (Arthur) Leslie (1910-2004) (stories)
- See www.theguardian.com/news/2004/apr/10/guardianobituaries
- Karl, Jean E(dna) (1927-2000) (stories)
- See www.sf-encyclopedia.com/entry/karl_jean_e
- Karlak, David (fl. 2010s) (stories) (assoc.)
- See www.davidkarlak.com
- Karlin, Nurit (1940-2019) (stories)
- See www.nytimes.com/2019/05/07/obituaries/nurit-karlin-dead.html
- Karloff, Boris; pseudonym of William Henry Pratt (1887-1969) (stories) (assoc.)
- See en.wikipedia.org/wiki/Karloff
- Karlson, Hans; pseudonym (stories)
- See www.sf-encyclopedia.com/entry/karlson_hans
- Karlsson, Janne (1973- ) (stories)
- See www.svenskapache.se
- Karney, Jack (1911- ) (stories) (assoc.)
- Born in New York City; worked in New York City D.A.s office.
- Karni, Yehuda [i.e., Yehuda Karni (Volovelski)] (1884-1949) (stories)
- See www.jewishvirtuallibrary.org/karni-volovelski-yehuda
- Karnow, Stanley (1925-2013) (stories)
- See en.wikipedia.org/wiki/Stanley_Karnow
- Karp, David (1922-1999) (stories) (assoc.)
- See www.sf-encyclopedia.com/entry/karp_david
- Karpyshyn, Drew (1971- ) (stories)
- See www.sf-encyclopedia.com/entry/karpyshyn_drew
- Karsavina, Tamara (Platonovna) (1885-1978) (stories) (assoc.)
- See en.wikipedia.org/wiki/Tamara_Karsavina
- Karsh, Yousuf (1908-2002) (stories) (art)
- See en.wikipedia.org/wiki/Yousuf_Karsh
- Karst, Leslie (fl. 2010s) (stories) (assoc.)
- See www.lesliekarstauthor.com
- Karunakaran, Sandeep (fl. 2010s) (art)
- See sanskarans.deviantart.com
- Kasai, Kirsten Imani (fl. 2000s-2010s) (stories) (assoc.)
- See www.icesong.com
- Kaser, Arthur Le Roy (1890-1956) (stories)
- Born in Indiana; published 463 works under his own name and 60 pseudonyms.
- Kashina, Anna (fl. 2000s-2010s) (stories) (assoc.)
- See en.wikipedia.org/wiki/Anna_Kashina
- Kassel, Mel (fl. 2010s) (stories)
- See melkassel.com
- Kastel, Roger (K.) (1931- ) (art)
- Born in White Plains, New York; lives in LaGrangeville, New York.
- Kastel, Warren; house pseudonym (fl. 1940s-1950s) (stories)
- See www.sf-encyclopedia.com/entry/kastel_warren
- Kastensmidt, Christopher (fl. 2000s-2010s) (stories)
- See www.eamb.org/the-author
- Kastin, Jonathan Lenore (fl. 2010s) (stories)
- See jonathanlenorekastin.com
- Kastin, Shawna Lenore (fl. 2010s) (stories)
- See shawnalenore.wordpress.com
- Kastle, Herbert D(avid) (1924-1987) (stories)
- See lynn-munroe-books.com/list59/herbertkastle.htm
- Kastura, Thomas (1966- ) (stories)
- See www.thomaskastura.de
- Kataev, Valentin (Petrovich) (1897-1986) (stories)
- See en.wikipedia.org/wiki/Valentin_Kataev
- Katayama, Sen [born Yabuki Sugataro] (1859-1933) (stories)
- See en.wikipedia.org/wiki/Sen_Katayama
- Katcher, Leo (1911-1991) (stories)
- Newspaper editor and reporter; writer of magazine fiction and non-fiction; film writer.
- Katchor, Ben (1951- ) (stories)
- See en.wikipedia.org/wiki/Ben_Katchor
- Katnik, Don (fl. 2000s-2010s) (stories)
- See thebark.com/content/qa-don-katnik
- Katsu, Alma (fl. 2010s) (stories) (assoc.)
- See www.almakatsu.com
- Katterjohn, Monte M. (1891-1949) (stories)
- See en.wikipedia.org/wiki/Monte_M._Katterjohn
- Katz, Andrew (fl. 2010s) (stories) (assoc.)
- See www.goodreads.com/author/show/299426.Andrew_Katz
- Katz, Arnold (fl. 1960s-1990s) (stories)
- See fancyclopedia.org/arnie-katz
- Katz, Fritz (fl. 1950s-1960s) (stories)
- Probably pseudonymous; not author, historian and educator Friedrich Katz (1927- ).
- Katz, Jack (1927- ) (stories) (assoc.)
- See en.wikipedia.org/wiki/Jack_Katz_(artist)
- Katzin, (Queenie) Olga (I.) (1896-1987) (stories)
- See bearalley.blogspot.co.uk/2016/04/olga-katzin.html
- Kauffman, Reginald Wright (1877-1959) (stories)
- Born and mostly lived in Lancaster, Pa.; graduate of Harvard; editor of Bangor, Maine, newspaper in 1940s.
- Kauffmann, Stanley (1916-2013) (stories)
- See en.wikipedia.org/wiki/Stanley_Kauffmann
- Kaufman, Al(fred) (1918-1977) (stories)
- See michaelmaslin.com/inkspill/al-kaufman-photos-surface/