Owls are in the order Strigifromes consisting of solitary and mostly nocturnal birds of prey. The two main families in this order are Strigidae (typical owls) with 23 living genera and Tytonidae (large heart shaped faced owls) with two genera. The genera for these two families are listed below.

Family Strigidae
Aegolius: saw-whet owls, four species
Asio: eared owls, 6–7 species
• Hawaiian Short-eared Owl Asio flammeus sandwichensis
• Long-eared Owl Asio otis
Athene:2–4 species burrowing owl
• Burrowing Owl Athene cunicularia
• Little Owl, German Owl Athene noctua
Bubo: horned owls, eagle-owls and fish-owls, some 25 species
• Great Horned Owl Bubo virginianus
• Greyish Eagle-Owl Bubo cinerascens
Ciccaba: four species
Glaucidium: pygmy-owls, about 30–35 species
• Pearl-spotted Owlet Glaucidium perlatum
Gymnoglaux: Bare-legged Owl or Cuban Screech-owl
Jubula: Maned Owl
Lophostrix: Crested Owl
Megascops: screech-owls, some 20 species
• Whiskered Screech Owl Megascops trichopsis
Micrathene
• Elf Owl Micrathene whitneyi
Mimizuku: Giant Scops-owl or Mindanao Eagle-owl
Ninox: Australasian hawk-owls, some 20 species
• Morepork, Tasmanian Spotted Owl Ninox novaeseelandiae
Nesasio - Fearful Owl
Otus: scops-owls; probably paraphyletic, about 45 species
• Common Screech Owl Otus asio
Pseudoscops: Jamaican Owl and possibly Striped Owl
Ptilopsis: white-faced owls, two species
Pulsatrix: spectacled owls, three species
• Northern White-faced Owl Ptilopsis leucotis
Pyrroglaux: Palau Owl
Strix: earless owls, about 15 species
• Great Grey Owl Strix nebulosa
Surnia: Northern Hawk-owl
Uroglaux: Papuan Hawk-owl
Xenoglaux: Long-whiskered Owlet

Family Tytonidae
• Barn Owl Tyto alba
Phodilus Bay owls