• Kaempfer's WoodpeckerCeleus obrieni
• KaguRhynochetos jubatus
• Kalahari Scrub-RobinCercotrichas paena
• Kalij PheasantLophura leucomelanos
• Kamchatka Leaf WarblerPhylloscopus examinandus
• Karoo EremomelaEremomela gregalis
• Karoo LarkCalendulauda albescens
• Karoo Long-billed LarkCerthilauda subcoronata
• Karoo PriniaPrinia maculosa
• Karoo ThrushTurdus smithi
• Kashmir FlycatcherFicedula subrubra
• Kauai AmakihiChlorodrepanis stejnegeri
• Kauai ElepaioChasiempis sclateri
• Kawall's AmazonAmazona kawalli
• Keel-billed MotmotElectron carinatum
• Keel-billed ToucanRamphastos sulfuratus
• Kelp GullLarus dominicanus
• Kemp's LongbillMacrosphenus kempi
• Kentucky WarblerGeothlypis formosa
• Kenya Rufous SparrowPasser rufocinctus
• Kermadec PetrelPterodroma neglecta
• Key West Quail-DoveGeotrygon chrysia
• Kilimanjaro White-eyeZosterops eurycricotus
• KilldeerCharadrius vociferus
• King Bird-of-ParadiseCicinnurus regius
• King EiderSomateria spectabilis
• King PenguinAptenodytes patagonicus
• King RailRallus elegans
• King-of-Saxony Bird-of-ParadisePteridophora alberti
• Kinglet ManakinMachaeropterus regulus
• Kirtland's WarblerSetophaga kirtlandii
• Klaas's CuckooChrysococcyx klaas
• Klages's AntbirdDrymophila klagesi
• Klages's AntwrenMyrmotherula klagesi
• Kloss's Leaf WarblerPhylloscopus ogilviegranti
• Knobbed HornbillRhyticeros cassidix
• Knysna TuracoTauraco corythaix
• Knysna WarblerBradypterus sylvaticus
• Koepcke's Screech-OwlMegascops koepckeae
• Koklass PheasantPucrasia macrolopha
• Krüper's NuthatchSitta krueperi
• Kurrichane ThrushTurdus libonyana