Kalama acalyptoides (Golub, 1975)
Kalama aethiops (Horváth, 1905)
Kalama aridula (Jakovlev, 1902)
Kalama beckeri (Jakovlev, 1871)
Kalama coriacea (Asanova, 1970)
Kalama cretica (Péricart, 1979)
Kalama froeschneri (Duarte Rodrigues, 1970)
Kalama iberica (Horváth, 1905)
Kalama kiritshenkoi Golub, 2005
Kalama levantina (Péricart, 1981)
Kalama lugubris (Fieber, 1861)
Kalama montisclari J. Ribes & Pagola-Carte, 2008
Kalama pusana (Drake & Maa, 1955)
Kalama reuteri (Horváth, 1906)
Kalama ribesi (Péricart, 1979)
Kalama tricornis (Schrank, 1801)
Kalama vinokurovi (Golub, 1979)
Kalama wangi Golub, Luo & Vinokurov, 2012
Kalmanius Benedek, 1969d, Subgenus (Nabis) – synonym of Nabicula Kirby, 1837, Subgenus (Nabis)
Kanigara clypeata (Distant, 1903)
Kanigara flavomarginata Distant, 1906
Kanigara tuberculata Scudder, 1969
Karamania balcanica Kormilev, 1938 – basionym of Artheneis balcanica (Kormilev, 1938)
Karenocoris granulus Hsiao & Ren, 1981
Karenocoris rudis Hsiao & Ren, 1981
Karocris morulus V.G. Putshkov, 1975
Kaschmirocoris klapperichi Hoberlandt, 1984
Kasumiphylus kyushuensis (Linnavuori, 1961)
Kasumiphylus ryukyuensis (Yasunaga, 1999)
Kelidocoris Kolenati, 1845, Subgenus (Globiceps)
Keliocoris wangi Ren, 1992b – basionym of Oncocephalus wangi (Ren, 1992)
Kerzhneriola asiatica hissarensis Josifov, 1979 – basionym of Atomoscelis asiatica hissarensis (Josifov, 1979)
Kerzhneriola asiatica Josifov, 1979 – basionym of Atomoscelis asiatica asiatica (Josifov, 1979)
Kerzhneroches Kiritshenko & Scudder, 1973, Subgenus (Parapolycrates)
Kiangsia elata Yang, 1934 – basionym of Paterculus elatus (Yang, 1934)
Kiiorthotylus Yasunaga, 1993, Subgenus (Orthotylus)
Kilicanata pilifera Seidenstücker, 1956a – synonym of Dasyscytus sordidus Fieber, 1864
Kirkaldyia deyrolli (Vuillefroy, 1864)
Kitocoris hahjima Yasunaga, 2000
Kleidocerys ericae (Horváth, 1908)
Kleidocerys franciscanus (non Stål, 1860, partly): – invalid name of Kleidocerys ericae (Horváth, 1908)
Kleidocerys nubilus (Distant, 1883)
Kleidocerys privignus (Horváth, 1894)
Kleidocerys pubescens Curtis, 1836 – synonym of Stygnocoris sabulosus (Schilling, 1829)
Kleidocerys resedae (Panzer, 1797)
Kleidocerys resedae resedae (Panzer, 1797)
Kleidocerys truncatulus (Walker, 1872)
Klinophilos horrifer Kirkaldy, 1899 – synonym of Cimex hemipterus (Fabricius, 1803)
Knightocapsus Wagner, 1963, Subgenus (Deraeocoris)
Kohnometopus fraxini Yasunaga, 2005 – invalid name of Kohnometopus fraxini Yasunaga, 2012
Kohnometopus fraxini Yasunaga, 2012
Kohnometopus yangi (C.S. Lin, 2005)
Kokeshia esakii Miyamoto, 1960
Kokeshia hsiaoi Ren & Zheng, 1992
Kokeshia xiei Rédei, Ren & Bu, 2012
Kokeshia zhengi Rédei, Ren & Bu, 2012
Koreocoris bicoloratus Cho & Kwon, 2008
Kotovelia kawakamii Matsumura, 1913 – basionym of Rhagovelia (Rhagovelia) kawakamii (Matsumura, 1913)
Ktenocoris Wagner, 1954, Subgenus (Phytocoris)