Search by letter: O
Search by letter
Search by letter: O
- O (letter) O
- Ö (O with diaeresis or umlaut) Ö
- O (Cyrillic letter) O (Cyrillic)
- O Brother, Where Art Thou? (2000) — film overview and significance O Brother, Where Art Thou? (movie)
- O Canada the national anthem of Canada
- O Holy Night — origin, music, and cultural impact O Holy Night
- O Lucky Man! — 1973 British satirical film by Lindsay Anderson O Lucky Man!
- O Rei do Gado
- O RLY? — an Internet reaction meme O RLY?
- O Tannenbaum (O Christmas Tree): German carol and cultural history O Tannenbaum
- O. Henry (William Sydney Porter): Master of the Short-Story Twist O. Henry
- O. Henry Award
- O. J. Simpson: Athlete, Actor, and Controversial Public Figure O. J. Simpson
- O. J. Simpson murder case (People of the State of California v. O. J. Simpson) O. J. Simpson murder case
- O. N. V. Kurup — Malayalam poet and lyricist O. N. V. Kurup
- O.N.I.F.C. — Wiz Khalifa's fourth studio album O.N.I.F.C.
- O'Brien County, Iowa
- O'Fallon, Illinois
- O'Hara Township, Allegheny County, Pennsylvania
- O'Hare International Airport
- O'Hare station train crash (March 24, 2014) O'Hare station train crash
- O'Hare (community area), Chicago O'Hare, Chicago
- O'Higgins Region (VI Region of Chile) O'Higgins Region
- O'Neal Compton
- O'Reilly Auto Parts 500 — NASCAR Cup Series race at Texas Motor Speedway O'Reilly Auto Parts 500
- O2 — diatomic oxygen, telecom brand, arenas, and other meanings O2
- Ö3 Austria Top 40
- Oʻahu — Hawaiian island and population, capital of the state Oahu
- Oak (Quercus): characteristics, uses, ecology and cultural role Oak
- Oak Brook, Illinois
- Oak Forest, Illinois: Overview and Local Profile Oak Forest, Illinois
- Oak Grove, Kentucky
- Oak Grove (West Carroll Parish, Louisiana) Oak Grove, West Carroll Parish, Louisiana
- Oak Harbor, Washington
- Oak Hill Cemetery (Lawrence, Kansas)
- Oak Hill, Alabama — small incorporated town in Wilcox County Oak Hill, Alabama
- Oak Hill, Florida
- Oak Island, North Carolina
- Oak Lawn, Illinois
- Oak Park, Illinois: architecture, history, and cultural highlights Oak Park, Illinois
- Oak Ridge Associated Universities (ORAU) Oak Ridge Associated Universities
- Oak Ridge, Tennessee
- Oak Woods Cemetery (Chicago) Oak Woods Cemetery
- Oakbrook Terrace, Illinois
- Oakdale, California
- Oakes, North Dakota
- Oakham, Rutland — county town and market centre in England Oakham
- Oakhurst, Oklahoma — small city profile Oakhurst, Oklahoma
- Oakland Acres, Iowa
- Oakland–Alameda County Coliseum (Oakland Coliseum) Oakland Alameda Coliseum
- Oakland Athletics: history, identity, and significance in American baseball Oakland Athletics
- Oakland Charter Township, Michigan: Overview and Community Profile Oakland Charter Township, Michigan
- Oakland City, Indiana
- Oakland County, Michigan
- Oakland Park, Florida
- Oakland Tribune
- Oakland, California: City overview and history Oakland, California
- Oakland, Chicago (community area) Oakland, Chicago
- Oakland, Florida — small town in Orange County within the Orlando metropolitan area Oakland, Florida
- Oakland, Illinois: overview, history, and local character Oakland, Illinois
- Oakland, Iowa: Overview, History, and Community Oakland, Iowa
- Oakland, Kentucky: a small incorporated city in south-central Kentucky Oakland, Kentucky
- Oakland, Nebraska
- Oakland, Oklahoma: small town overview and local profile Oakland, Oklahoma
- Oakley, Idaho — small city in Cassia County Oakley, Idaho
- Oakley, Kansas
- Oaks, Oklahoma
- Oakville, Alabama — unincorporated community in Lawrence County Oakville, Alabama
- Oakville, Iowa — small city profile and community overview Oakville, Iowa
- Oakville, Ontario: overview, history, neighbourhoods and notable features Oakville, Ontario
- Oakwell — Barnsley stadium and sports complex Oakwell
- Oakwood tube station (Piccadilly line, London) Oakwood tube station
- Oakwood, Oklahoma
- Ōan: Japanese era of the Northern Court, 1368–1375 Ōan
- Oar: design, types, history and use Oar
- Oarfish (Regalecidae): ribbonlike deep‑sea fishes and their history Oarfish
- Oasis: desert settlements around water and vegetation Oasis
- Oasis (English rock band) Oasis (band)
- Oasis discography and release history Oasis discography
- Oasis LRT Station (PE6) — Punggol light rail stop in Singapore Oasis LRT Station
- Oat (Avena sativa): description, cultivation, uses and nutritional role Oat
- Oath
- Oath of Office: Purpose, Forms, History, and Legal Significance Oath of office
- Oath of Office of the President of the United States
- Oatmeal: types, preparation, nutrition, and culinary uses Oatmeal
- Oaxaca (Mexican state) Oaxaca
- Oaxaca de Juárez: capital city of Oaxaca and cultural center Oaxaca de Juárez
- Ob (river)
- OB star
- Oba Chandler: overview of the case, investigation, trial and legacy Oba Chandler
- Obadele Thompson: Barbadian Olympic Sprinter and 2000 100m Bronze Medalist Obadele Thompson
- Obafemi Martins
- Obama, Fukui — coastal city on the Sea of Japan Obama, Fukui
- Oban: Gateway to the Isles in Argyll and Bute Oban
- Obazoa: a proposed eukaryote clade linking opisthokonts, apusomonads and breviates Obazoa
- Obdurodon: an extinct toothed monotreme genus Obdurodon
- Obed Mfanyana Dlamini Obed Dlamini
- Obelisk: form, history, and cultural significance Obelisk
- Obelus (÷): symbol, history, forms and uses Obelus
- Oberaargau (administrative district)
- Oberägeri — lakeside municipality in the canton of Zug, Switzerland Oberägeri
- Oberallgäu: rural district in Swabia, Bavaria Oberallgäu
- Oberbalm (municipality in Bern, Switzerland) Oberbalm
- Oberbergischer Kreis
- Oberbipp (Canton of Bern, Switzerland) Oberbipp
- Oberblegisee
- Oberbözberg (former Swiss municipality) Oberbözberg
- Oberbruck (Haut-Rhin): overview, history and visitor guide Oberbruck
- Oberbuchsiten, municipality in the Gäu district of Solothurn, Switzerland Oberbuchsiten
- Oberbüren — municipality in Wil district, canton of St. Gallen Oberbüren
- Oberburg (Emmental, Canton of Bern) Oberburg
- Oberdan Cattani — Brazilian goalkeeper and Palmeiras icon Oberdan Cattani
- Oberdiessbach: Swiss municipality in Bern-Mittelland Oberdiessbach
- Oberdorf (Basel-Landschaft): overview of the Swiss municipality Oberdorf, Basel-Landschaft
- Oberdorf, Haut-Rhin
- Oberdorf, Nidwalden: a rural municipality in central Switzerland Oberdorf, Nidwalden
- Oberdorf (Solothurn) — Municipality in Lebern District, Switzerland Oberdorf, Solothurn
- Oberegg — district and exclave of Appenzell Innerrhoden, Switzerland Oberegg
- Oberembrach — municipality in the canton of Zürich Oberembrach
- Oberems — Mountain municipality in the canton of Valais, Switzerland Oberems
- Oberengstringen (municipality in the canton of Zürich) Oberengstringen
- Oberentfelden — Municipality in the Canton of Aargau, Switzerland Oberentfelden
- Oberentzen, Haut-Rhin (Alsace) — commune in northeastern France Oberentzen
- Obererlinsbach (former Swiss municipality) Obererlinsbach
- Oberflachs: former Swiss municipality in Aargau (now part of Schinznach) Oberflachs
- Obergefell v. Hodges (2015) Obergefell v. Hodges
- Obergerlafingen
- Obergesteln — village in the Goms valley, Valais (former Swiss municipality) Obergesteln
- Oberglatt, municipality in Dielsdorf district, Canton of Zürich Oberglatt
- Obergoms (Valais, Switzerland) Obergoms
- Obergösgen (municipality in Solothurn, Switzerland) Obergösgen
- Oberhaching: municipality south of Munich in Upper Bavaria Oberhaching
- Oberhallau: Swiss municipality in the canton of Schaffhausen Oberhallau
- Oberhasli district, Bern (Haslital) — geography, municipalities and overview Oberhasli (district)
- Oberhausen, Germany — city in the Ruhr Area Oberhausen
- Oberhavel district, Brandenburg, Germany Oberhavel
- Oberhelfenschwil — municipality in Toggenburg, canton of St. Gallen Oberhelfenschwil
- Oberhergheim (Haut-Rhin) Oberhergheim
- Oberhof, Aargau: municipality in the district of Laufenburg, Switzerland Oberhof, Aargau
- Oberhofen am Thunersee — lakeside municipality in Canton Bern Oberhofen am Thunersee
- Oberhofen (Aargau) — former municipality in Mettauertal Oberhofen, Aargau
- Oberhünigen — municipality in the canton of Bern, Switzerland Oberhünigen
- Oberiberg (Schwyz, Switzerland) Oberiberg
- Oberkirch, Lucerne: a Swiss municipality near Lake Sempach Oberkirch, Switzerland
- Oberkulm — municipality in the district of Kulm, Aargau, Switzerland Oberkulm
- Oberlangenegg, Bern: Municipality in Thun District, Switzerland Oberlangenegg
- Oberlarg — small commune in Haut-Rhin, Grand Est, France Oberlarg
- Oberlin College
- J. F. Oberlin University (Obirin) — Private university in Machida, Tokyo Oberlin University
- Oberlin, Kansas — County seat and rural community Oberlin, Kansas
- Oberlin, Louisiana — Parish Seat of Allen Parish Oberlin, Louisiana
- Oberlin, Ohio — college town and historic community Oberlin, Ohio
- Oberlungwitz, Saxony: town overview and local profile Oberlungwitz
- Oberlunkhofen (Aargau) Oberlunkhofen
- Obermaiselstein: Alpine municipality in Oberallgäu, Bavaria Obermaiselstein
- Obermorschwihr
- Obermorschwiller: commune in Haut-Rhin, Alsace (Grand Est), France Obermorschwiller
- Obermumpf: municipality in the canton of Aargau, Switzerland Obermumpf
- Oberndorf am Lech
- Oberon — King of the Fairies in Literature and Culture Oberon
- Oberon (moon)
- Oberönz — former municipality in the canton of Bern, Switzerland Oberönz
- Oberösch — former municipality in Emmental, canton of Bern Oberösch
- Oberpullendorf District — administration, geography and culture Oberpullendorf District
- Oberramsern (former municipality in Solothurn, Switzerland) Oberramsern
- Oberreute (Allgäu) — municipality and air health resort in Bavaria Oberreute
- Oberried: name, etymology and principal localities Oberried
- Oberried am Brienzersee — lakeside municipality in Interlaken-Oberhasli, canton of Bern Oberried am Brienzersee
- Oberrieden — place name in German-speaking Europe Oberrieden
- Oberrieden (Canton Zurich): Lakeside Municipality between the Sihl River and Lake Zurich Oberrieden, Switzerland
- Oberriet, Rheintal — municipality in the canton of St. Gallen, Switzerland Oberriet
- Oberrohrdorf — municipality in the canton of Aargau, Switzerland Oberrohrdorf
- Oberrüti — Municipality in Muri District, Canton Aargau, Switzerland Oberrüti
- Obersaasheim (commune in Haut-Rhin, France) Obersaasheim
- Obersaxen (Sursaissa) Obersaxen
- Obersaxen Mundaun — municipality in Surselva, Graubünden Obersaxen Mundaun
- Oberschleißheim: Municipality and Schleissheim Palace near Munich Oberschleißheim
- Oberschrot (former municipality in the canton of Fribourg, Switzerland) Oberschrot
- Obersiggenthal, Aargau — Swiss municipality overview Obersiggenthal
- Obersimmental District, Canton of Bern Obersimmental District
- Obersimmental-Saanen (administrative district, canton of Bern) Obersimmental-Saanen (administrative district)
- Oberspreewald-Lausitz
- Oberstammheim (former municipality in the canton of Zürich) Oberstammheim
- Oberstaufen — Alpine municipality in the Allgäu region of Bavaria Oberstaufen
- Oberstdorf: Alpine town and resort in the Allgäu Alps Oberstdorf
- Obersteckholz
- Oberstocken — former municipality in the canton of Bern, Switzerland Oberstocken
- Oberstrass: Quarter of Zürich’s District 6 Oberstrass
- Oberthal, Saarland
- Oberthal (Bern) — municipality in the canton of Bern, Switzerland Oberthal, Switzerland
- Obertshausen — town in the Offenbach district, Hesse Obertshausen
- Oberurnen — former municipality in the canton of Glarus, Switzerland Oberurnen
- Oberuzwil: Municipality in the District of Wil, Canton of St. Gallen Oberuzwil
- Oberwald — Alpine village in Goms, Valais, Switzerland Oberwald
- Oberwart District (Bezirk Oberwart) — southern Burgenland, Austria Oberwart District
- Oberweningen — Municipality in Dielsdorf District, Canton of Zürich, Switzerland Oberweningen
- Oberwil bei Büren — municipality in Seeland, Canton of Bern Oberwil bei Büren
- Oberwil im Simmental
- Oberwil-Lieli: Municipality in the Canton of Aargau, Switzerland Oberwil-Lieli
- Oberwil (Basel-Landschaft) Oberwil, Basel-Landschaft
- Oberwinterthur — District 2 of Winterthur, Switzerland Oberwinterthur
- Obesity: causes, measurement, health effects, prevention and treatment Obesity
- Obfelden — municipality in the district of Affoltern, canton of Zürich Obfelden
- Obfuscation: definitions, methods, history, and impacts Obfuscation
- Obi: the Japanese sash—types, history, tying methods and cultural role Obi
- Obi-Wan Kenobi: Jedi Master, Mentor, and Cultural Icon Obi-Wan Kenobi
- Obie Trice — American rapper, songwriter and Detroit native Obie Trice
- Obion County, Tennessee
- Obituary: purpose, form, history and uses Obituary
- Object: definitions, varieties, and uses across disciplines Object
- Object (computer science)
- Grammatical object: direct, indirect, and other kinds Object (grammar)
- Object-oriented programming (OOP): concepts, history, and applications Object-oriented programming
- Objective-C (programming language) Objective-C
- Objectivism: meanings, philosophical forms, and cultural uses Objectivism
- Objectivism (Ayn Rand)
- Objectivity: meanings, criteria, history, and practical roles Objectivity
- Objectivity in Journalism Objectivity (journalism)
- Objectivity (philosophy): concept, forms, and debates Objectivity (philosophy)
- Objectivity in Science: Principles, Practices, and Limits Objectivity (science)
- Oblast: administrative region in Slavic and post‑Soviet countries Oblast
- Oblasts of Ukraine
- Oblate spheroid: geometry, causes, and examples Oblate spheroid
- Oblinghem — commune in Pas-de-Calais, northern France Oblinghem
- Oblique order (military tactic) Oblique order
- Oblique type: definition, characteristics, history and uses Oblique type
- Oblivion (2013 film) Oblivion (2013 movie)
- Obock Region (Djibouti) Obock Region
- Oboe: construction, sound, history, repertoire and variants Oboe
- Obscenity: definitions, history, legal standards, and cultural debates Obscenity
- Observable universe: definition, size, history, and scientific importance Observable universe
- Observation: Processes, Tools, History, and Scientific Role Observation
- Observation deck — elevated viewing platforms Observation deck
- Observatory
- Observe and Report (2009 film) Observe and Report
- Observer effect: measurement disturbance and observer bias Observer effect
- Obsessed (Mariah Carey song) Obsessed
- Obsessive–compulsive personality disorder Obsessive-compulsive personality disorder
- Obsessive–Compulsive Disorder (OCD): Overview, Symptoms and Treatment Obsessive–compulsive disorder
- Obsidian
- Obsidian Entertainment
- Obstacle Course: Types, Design, History and Uses Obstacle course
- Obstalden — former municipality in Glarus, Switzerland Obstalden
- Obstetric fistula: causes, symptoms, treatment and prevention Obstetric fistula
- Obstetrics
- Obstruction of Justice: Definition, Forms, and Legal Context Obstruction of justice
- Obtuse angle
- Obwalden: central Swiss canton centered on Sarnen Obwalden
- Ocala, Florida — county seat, equine center, and gateway to springs and forests Ocala, Florida
- OCaml (Objective Caml) OCaml
- Ocarina: the vessel flute — design, history and uses Ocarina
- Očauš: a mountain of central Bosnia Očauš
- Occam's razor
- Occidental College: history, academics, campus, and notable alumni Occidental College
- Occidental Mindoro — province on the western half of Mindoro, Philippines Occidental Mindoro
- Occipital bone — anatomy, function, and clinical relevance Occipital bone
- Occipital lobe
- Occitan language (lenga d'òc) — Romance language of southern Europe Occitan language
- Occitan Wikipedia
- Occitanie — Region of France and the Occitania cultural area Occitanie
- Occluded front
- Occoquan, Virginia: historic riverfront town and arts community Occoquan, Virginia
- Occult: Concepts, Practices, and Historical Context Occult
- Occultation (astronomy and general): definition, types, and significance Occultation
- Occupation: meanings, types, legal and military senses, and social roles Occupation
- Occupation of Czechoslovakia (1938–1945)
- Occupational Safety and Health
- Occupational Safety and Health Administration (OSHA) Occupational Safety and Health Administration
- Occupied territory (military occupation) Occupied territory
- Occupy movement: grassroots protests against economic and social inequality Occupy movement
- Occupy Wall Street (2011 protest movement) Occupy Wall Street
- Ocean
- Ocean acidification
- Ocean City, Maryland: Resort town on the Atlantic coast Ocean City, Maryland
- Ocean City, New Jersey — family resort and coastal community Ocean City, New Jersey
- Ocean County, New Jersey
- Ocean current
- Ocean gyre: large-scale circular ocean current systems Ocean gyre
- Ocean liner: design, history, and distinction from cruise ships Ocean liner
- Ocean Master (Orm Marius) — DC Comics supervillain and Aquaman's half-brother Ocean Master
- Ocean Springs, Mississippi
- Ocean sunfish (Mola mola): description, behavior, and ecological role Ocean sunfish
- Ocean surface wave
- Ocean thermal energy conversion (OTEC): principles, systems, and applications Ocean thermal energy conversion
- Ocean's Eleven (2001 film) Ocean's Eleven
- Ocean's Twelve (2004) — overview of the heist sequel Ocean's Twelve
- Oceana County, Michigan
- Oceania: geography, regions, biogeography and political definitions Oceania
- Oceania Football Confederation (OFC) Oceania Football Confederation
- Oceanic climate (maritime climate) Oceanic climate
- Oceanic crust: composition, formation, and lifecycle Oceanic crust
- Oceanic dolphins (family Delphinidae) Oceanic dolphin
- Oceanic trench
- Oceanic whitetip shark (Carcharhinus longimanus) Oceanic whitetip shark
- Oceanography: The Science of the Seas and Marine Environment Oceanography
- Oceanside, California: coastal city in northern San Diego County Oceanside, California
- Oceanus Hopkins — infant born aboard the Mayflower Oceanus Hopkins
- Ocellated turkey (Meleagris ocellata) Ocellated turkey
- Ocelot (Leopardus pardalis): description, range, behavior and conservation Ocelot
- Ochancourt — commune in the Somme department of northern France Ochancourt