| Opsaridium | Opsaridium boweni | Opsaridium engrauloides |
| Opsaridium leleupi | Opsaridium loveridgii | Opsaridium maculicauda |
| Opsaridium microcephalum | Opsaridium microlepis | Opsaridium peringueyi |
| Opsaridium splendens | Opsaridium tweddleorum | Opsaridium ubangiense |
| Opsaridium zambezense | Opsariichthys | Opsariichthys bea |
| Opsariichthys bidens | Opsariichthys dienbienensis | Opsariichthys duchuunguyeni |
| Opsariichthys elegans | Opsariichthys evolans | Opsariichthys hainanensis |
| Opsariichthys hieni | Opsariichthys kaopingensis | Opsariichthys minutus |
| Opsariichthys pachycephalus | Opsariichthys songmaensis | Opsariichthys steenackeri |
| Opsariichthys uncirostris | Opsarius | Opsarius barna |
| Opsarius barnoides | Opsarius bernatziki | Opsarius cocsa |
| Opsarius koratensis | Opsarius maculatus | Opsarius nelsoni |
| Opsarius pulchellus | Opsarius tileo | Opsaroa |
| Opsaroa fulvinota | OPSB | OPSBI |
| OPSCC | Opsci | Opscode |
| OPSD | OPSEC | Opsec |
| OpSec | OPSEK | Opsenica |
| Opseogymnus | Opseth | OPSEU |
| Opsherin | Opshop | OpShop |
| Opshtina | OPSI | Opsi |
| OPSI (disambiguation) | Opsi (open pc server integration) | Opsia Araba |
| Opsia gens | Opsiandra | Opsibidion |
| Opsibidion albifasciatum | Opsibidion albinum | Opsibidion flavocinctum |
| Opsibotys | Opsibotys benenotata | Opsibotys flavidecoralis |
| Opsibotys fuscalis | Opsibotys hasanensis | Opsibotys latipennis |
| Opsibotys ocellalis | Opsibotys profusalis | Opsicarpium |
| Opsicarpium insignis | Opsician | Opsician Theme |
| Opsician theme | Opsicians | Opsicion |
| Opsiclines | Opsiclines leucomorpha | Opsida Sigecka |
| Opsida sigecka | Opsidia gens | Opsidiscidae |
| Opsieobuthus | Opsieobuthus tungeri | Opsies |
| Opsies capra | Opsigalea | Opsigalea blanchardi |
| Opsiini | Opsikion | Opsikion theme |
| Opsilia | Opsilia aspericollis | Opsilia badenkoi |
| Opsilia bucharica | Opsilia chinensis | Opsilia coerulescens |
| Opsilia gens | Opsilia irakensis | Opsilia longitarsis |
| Opsilia malachitica | Opsilia molybdaena | Opsilia prasina |
| Opsilia schurmanni | Opsilia transcaspica | Opsilia uncinata |
| Opsilia varentzovi | Opsilia virescens | Opsimath |
| Opsimaths | Opsimathy | Opsimini |
| Opsimus | Opsimus quadrilineatus | Opsin |
| Opsin 4 | Opsin kinase | Opsin kinase (phosphorylating) |
| Opsine | Opsins | Opsioleus adversus |
| Opsiomyia | Opsiphanes | Opsiphanes blythekitzmillerae |
| Opsiphanes cassiae | Opsiphanes cassina | Opsiphanes sallei |
| Opsiphanes singularis | Opsiplanon | Opsiplanon luellus |
| Opsirhina | Opsirhina albigutta | Opsirhina lechriodes |
| Opsirhina metallescens | Opsirhina metaphaea | Opsirhina tintinarra |
| Opsis | Opsismodysplasia | Opsistylis |
| Opsite | OpSite | Opsites |
| Opsites of Lazica | Opsithrissops | Opsitycha squalidella |
| Opsius | Opsius stactogalus | Opsječko |
| Opsjecko | Opsk | OPSK |
| OPSkins | OPSM | OPSN |
| Opsoclonic cerebellopathy | Opsoclonus | Opsoclonus Myoclonus |
| Opsoclonus myoclonus | Opsoclonus Myoclonus Ataxia | Opsoclonus myoclonus ataxia |
| Opsoclonus myoclonus syndrome | Opsoclonus Myoclonus syndrome | Opsoclonus-myoclonus syndrome |
| Opsodoca | Opsodoras | Opsodoras steindachneri |
| Opsodoras stuebelii | Opsoempheria | Opsoleskia |
| Opsomantis | Opsomeigenia | Opsommer, Paul |
| Opsomyoclonus | Opson | Opsona Therapeutics |
| Opsonin | Opsonin proteins | Opsonins |
| Opsonisation | Opsonization | Opsonize |
| Opsonized | Opsonizer | Opsophagos |
| Opsophagus | Opsophagus nigripalpis | Opsophagus ornatus |
| Opsophasiopteryx | Opsopoeodus | Opsopoeodus bollmani |
| Opsopoeodus emiliae | Opsosturmia | Opsotheresia |
| Opsotheresia bigelowi | Opsotheresia nigricornis | Opsotheresia obesa |
| Opsound | OpSource | Opsozelia |
| OPSR | OPSS | OPSS (disambiguation) |
| Opst | OPST | Opstad |
| Opstad Forced Labor Institution | Opstad, Mark | Opstead, Minnesota |
| Opsterland | Opstibranchia | Opstina |
| Opstina Ada | Opstina Alibunar | Opstina Apatin |
| Opstina Aracinovo | Opstina Aracinovo, Republic of Macedonia | Opstina Bac |
| Opstina Bac, Republic of Macedonia | Opstina Backa Palanka | Opstina Backa Topola |
| Opstina Backi Petrovac | Opstina Barajevo | Opstina Becej |
| Opstina Bela Crkva | Opstina Belcista | Opstina Belcista, Republic of Macedonia |
| Opstina Bistrica | Opstina Bogdanci | Opstina Bogdanci, Republic of Macedonia |
| Opstina Bogomila | Opstina Bogovinje | Opstina Bogovinje, Republic of Macedonia |
| Opstina Bosilovo | Opstina Bosilovo, Republic of Macedonia | Opstina Brvenica |
| Opstina Brvenica, Republic of Macedonia | Opstina Capari | Opstina Capari, Republic of Macedonia |
| Opstina Caska | Opstina Caska, Republic of Macedonia | Opstina Cegrane |
| Opstina Cesinovo | Opstina Coka | Opstina Cucer-Sandevo |
| Opstina Cucer-Sandevo, Republic of Macedonia | Opstina Delcevo | Opstina Delcevo, Republic of Macedonia |
| Opstina Demir Hisar | Opstina Demir Hisar, Republic of Macedonia | Opstina Demir Kapija |
| Opstina Demir Kapija, Republic of Macedonia | Opstina Dobrusevo | Opstina Dolna Banjica |
| Opstina Dolneni | Opstina Dolneni, Republic of Macedonia | Opstina Drugovo |
| Opstina Drugovo, Republic of Macedonia | Opstina Dzepciste | Opstina Gradsko |
| Opstina Gradsko, Republic of Macedonia | Opstina Grocka | Opstina Ilinden |
| Opstina Ilinden, Republic of Macedonia | Opstina Izvor | Opstina Jegunovce |
| Opstina Jegunovce, Republic of Macedonia | Opstina Kamenjane | Opstina Kamenjane, Republic of Macedonia |
| Opstina Kanjiza | Opstina Karbinci | Opstina Karbinci, Republic of Macedonia |
| Opstina Karpos | Opstina Karpos, Republic of Macedonia | Opstina Kikinda |
| Opstina Kisela Voda | Opstina Kisela Voda, Republic of Macedonia | Opstina Konce |
| Opstina Konce, Republic of Macedonia | Opstina Kondovo | Opstina Konopiste |
| Opstina Kosel | Opstina Kosel, Republic of Macedonia | Opstina Kosovo Polje |
| Opstina Kovacica | Opstina Kovin | Opstina Kratovo |
| Opstina Kratovo, Republic of Macedonia | Opstina Krivogastani | Opstina Krivogastani, Republic of Macedonia |
| Opstina Kuklis | Opstina Kukurecani | Opstina Kula |
