- obductella, Uncinus
- obelisca, Euxoa
- obeliscata, Thera
- obesalis, Hypena
- obfuscata, Gnophos
- obliquella, Elachista
- obliquella, Stigmella
- oblitella, Ancylosis
- oblonga, Apamea
- oblongana, Endothenia
- obscenella, Coleophora
- obscuralis, Parapoynx
- obscurana, Pammene
- obscurata, Charissa
- obscurepunctella, Perittia
- obsitalis, Hypena
- obsoleta, Leucania
- obsoletana, Phiaris
- obsoletella, Scrobipalpa
- obstipata, Orthonama
- obtusa, Pelosia
- obtusana, Ancylis
- obumbratana, Eucosma
- obviella, Monopis
- occidentis, Lobesia
- occulta, Eurois
- occultella, Ectoedemia
- ocellana, Agonopterix
- ocellana, Spilonota
- ocellaris, Xanthia
- ocellata, Cosmorhoe
- ocellata, Smerinthus
- ocellatella, Scrobipalpa
- ocellea, Euchromius
Ochlodes
- ochraceella, Mompha
- ochraceella, Myrmecozela
- ochrata, Idaea
- ochrea, Coleophora
- ochrearia, Aspitates
- ochrodactyla, Gillmeria
- ochroleuca, Eremobia
- ochroleucana, Hedya
Ochropacha
Ochropleura
Ochyria
Ocnerostoma
Odezia
Odonestis
Odontopera
Odontosia
Oecophora
Oidaematophorus
Oinophila
Olepa
Olethreutes
Olindia
Oncocera
Operophtera
Ophiusa
Opisthograptis
Opogona
Opostega
- oppressana, Gypsonoma
- or, Tethea
- orana, Adoxophyes
- orbitella, Coleophora
- orbona, Noctua
- orbonalis, Leucinodes
Orgyia
Oria
- orichalcea, Cosmopterix
- orichalcea, Thysanoplusia
- orientalis, Ceratophaga
- ornata, Scopula
- ornatella, Pempeliella
- ornitopus, Lithophane
- orobana, Grapholita
- orobi, Leucoptera
Orodesma
Ortholepis
Orthonama
Orthosia
Orthotaenia
Orthotelia
- osseana, Eana
- osseatella, Euzophera
- osseella, Psamathocrita
- osseola, Hydraecia
- osteodactylus, Hellinsia
- osthelderi, Catoptria
- ostrina, Eublemma
- ostrinalis, Pyrausta
Ostrinia
Ourapteryx
Oxyptilus
155 species