- Kadavu Fantail
- Kadavu Honeyeater
- Kalahari Scrub Robin
- Kalij Pheasant
- Karoo Long-billed Lark
- Karoo Prinia
- Karoo Thrush
- Kea
- Kelp Gull
- Kentish Plover
- Kentucky Warbler
- Kenya Sparrow
- Kessler's Thrush
- Kikau
- Kikuyu White-eye
- Killdeer
- King Bird-of-paradise
- King Eider
- King Vulture
- Kinglet Manakin
- Kittlitz's Murrelet
- Kittlitz's Plover
- Klaas's Cuckoo
- Kloss's Leaf Warbler
- Knob-billed Duck
- Knob-billed Fruit Dove
- Koklass Pheasant
- Kori Bustard
- Krüper's Nuthatch
- Kurrichane Thrush