| Kakopoda Smith | 930994 | |
| Kallitrichia Ottolengui | 931698 | |
| kappa Barnes & Benjamin, Lacinipolia, [Polia] | 933045 | |
| 10066.2 | kappa Grote, Sympistis, [Homohadena] | 931824 | |
| karschi Graeser, Euxoa, [Agrotis] | 933424 | |
| kasloa Smith, Schinia, [Melicleptria] | 932102 | |
| kasloa Dyar, Spilosoma– ssp., [Diacrisia] | 930313 | |
| kasloensis Strand, Autographa | 931203 | |
| 9750.1 | kathyae Adams, Plagiomimicus | 931657 | |
| 10581 | keela Smith, Pseudorthodes, [Orthodes] | 933131 | |
| 10935 | keelei Gibson, Parabarrovia | 933621 | |
| 9460 | keiferi Benjamin, Amphipoea, [Apamea] | 932451 | |
| 10075 | kelloggii Edwards, Sympistis, [Anarta] | 931943 | |
| 10063.1 | kelsoensis Robertson & Mustelin, Sympistis, [Oncocnemis] | 931829 | |
| kendalli Riotte, Orgyia | 930165 | |
| 8061 | kentuckiensis Dyar, Cisthene, [Illice] | 930178 | |
| kerrvillei Barnes & McDunnough, Dasychira– ssp., [Olene] | 930150 | |
| kerrvillei Smith, Euxoa, [Carneades] | 933354 | |
| ketchikana Barnes & Benjamin, Cucullia, [Rancora] | 931536 | |
| Khadira Moore | 930623 | |
| 10104.3 | khem Troubridge, Sympistis | 931891 | |
| 10147.2 | khepri Troubridge, Sympistis | 931813 | |
| kieferi Rebel, Coenophila, [Agrotis] | 933624 | |
| 10649 | kingi McDunnough, Agrotis | 933513 | |
| 11014 | kirkwoodi Buckett, Abagrotis | 933651 | |
| klagesii Ehrmann, Estigmene, [Leucarctia] | 930317 | |
| klotsi Edwards, Drasteria– ssp. | 930889 | |
| klotsi Richards, Lasionycta, [Lasiestra] | 933003 | |
| 9139 | knowltoni McDunnough, Tarache, [Acontia] | 931346 | |
| 9937 | knowltoni McDunnough, Eupsilia | 932592 | |
| knoxvillea McDunnough, Euxoa | 933384 | |
| 10629.1 | knudsoni Crabo & Lafontaine, Tricholita | 933196 | |
| 10147.1 | knudsoni Troubridge, Sympistis | 931812 | |
| Kodiosoma Stretch | 930431 | |
| 9779 | koebelei Riley, Argentostiria, [Antaplaga] | 931758 | |
| kolthoffi Aurivillius, Sympistis– ssp., [Anarta] | 931931 | |
| kolthoffi Bryk, Lymantria | 930141 | |
| 10987.1 | kolymae Herz, Xestia, [Agrotis] | 933603 | |
| Konokareha Matsumura | 930141 | |
| 8128.1 | kononenkoi Tshistjakov & Lafontaine, Dodia | 930339 | |
| koreiba Bryk, Lymantria | 930141 | |
| kozhantshikovi Sheljuzhko, Dodia, [Hyperborea] | 930337 | |
| krautwormi Chermock, Acronicta, form | 931474 | |
| krombeini Franclemont, Catocala | 930807 | |
| kurilana Bryk, Xestia, [Diarsia] | 933588 | |
| kurilirena Bryk, Apamea, [Crymodes] | 932353 | |
| kurodakeana Matsumura, Sympistis | 931910 | |
| 10880 | kyune Barnes, Dichagyris, [Hadena] | 933245 | |
