222 Nouns that Start with O in English

Are you looking for a list of nouns that start with O? Actually, there are manywords that start with Oin the English language. Don’t fret, though. We don’t expect you to merely take these words for it. Instead, stick around and read on to the next section. It is a list containing various nouns starting with the letter O.

Nouns That Start with O


O isn’t necessarily a letter that people think about words starting with. In fact, you might believe there aren’t many nouns, verbs, or adjectives that begin with the fifteenth letter of the alphabet. However, there are many nouns that start with O, some common examples include ocean, octopus, onion, opera, office, oven, orchid, orb, oyster, and observatory.

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Common Nouns That Start with O

Nouns Examples
Oak Theoaktree was more than 300 years old.
Oar He used anoarto paddle the boat.
Oasis Theoasisprovided a much-needed respite from the desert heat.
Oat The farmer plantedoatsin the field to feed his livestock.
Oath He took anoathto tell the truth in court.
Obelisk Theobeliskstood tall in the city square.
Object She picked up theobjectand examined it closely.
Obligation It’s myobligationto take care of my elderly parents.
Observation Through carefulobservation,she was able to identify the bird species.
Observatory Theobservatorywas equipped with state-of-the-art telescopes.
Obstacle The fallen tree was anobstaclein our path.
Occasion We dressed up for the specialoccasion.
Occupation His占领was a firefighter.
Ocean Theoceanstretched out before them, vast and blue.
Octave The song was written in a highoctave.
Octopus Theoctopuschanged colors to blend in with its surroundings.
Odor Theodorcoming from the trash can was unbearable.
Offense The team’s进攻was too strong for the opposing team to handle.
Office She worked in a busyofficedowntown.
Officer The policeofficerpulled over the speeding car.
Official Theofficialannouncement was made at a press conference.
Oil The car needed anoilchange.
Okra She fried theokrauntil it was crispy and golden brown.
Olive The salad was garnished with slices of ripe greenolives.
Omen The black cat crossing their path was seen as anomenof bad luck.
Onset Theonsetof winter brought cold temperatures and snow.
Opera Theoperawas a grand production with elaborate costumes and sets.
Operation The surgicaloperationwas a success.
Operator The phoneoperatorconnected the call to the correct department.
Opinion Everyone is entitled to their ownopinion.
Opportunity She saw the job opening as anopportunityto advance her career.
Opposition Theoppositionparty had different ideas on how to run the country.
Option The menu had a vegetarianoption.
Orange Theorangewas juicy and sweet.
Orbit The satellite was in a stableorbitaround the earth.
Orchestra Theorchestraplayed a beautiful symphony.
Order She placed anorderfor a pizza with extra cheese.
Ordinary The day was just anordinaryday, nothing special happened.
Organ Theorganwas the largest instrument in the church.
Organization Theorganizationwas dedicated to helping those in need.
Origin Theoriginof the custom is shrouded in mystery.
Ornament The tree was decorated with colorfulornamentsfor the holidays.
Orphan Theorphanwas taken in by a kind-hearted family.
Ostrich Theostrichis the largest bird in the world.
Other Theothersin the group were all doctors, but he was a lawyer.
Otter The playfulotterswam in the pond.
Outcome Theoutcomeof the election was surprising to many people.
Outlet She plugged the lamp into the electricaloutlet.
Oval The track for the race is anovalthat measures 400 meters in length.
Oven She baked a batch of cookies in theoven.
Owl Theowlhooted softly in the night.
Owner Theownerof the store greeted customers with a smile.
Ox Theoxenpulled the heavy cart up the hill.
Oxygen The doctor gave her a dose ofoxygento help her breathe.

Abstract Nouns That Start with O

Nouns Examples
Objectivity The news should be reported withobjectivityand impartiality.
Oblivion The famous singer fell intooblivionafter his scandalous behavior.
Obscurity The author’s work remained inobscurityuntil it was discovered years later.
Observation The scientist made a carefulobservationof the behavior of the monkeys.
Occasion The wedding was a joyousoccasionfor the whole family.
Odyssey The book tells the story of an epicodysseyacross the ocean.
Offense The athlete apologized for his unintentional进攻against the other team.
Offering The churchgoers broughtofferingsto the altar during the service.
Offspring The proud parents watched as theiroffspringgraduated from college.
Oneness The spiritual leader spoke about the importance of achieving a sense ofonenesswith the universe.
Openness The manager encouraged an atmosphere ofopennessand honesty in the workplace.
Opportunity The scholarship provided anopportunityfor the student to attend college.
Opposition The two political parties are inoppositionon many issues.
Optimism Despite the setbacks, the team maintained anoptimisticoutlook for the future.
Option The menu offered a vegetarianoptionfor those who did not eat meat.
Order The waiter took ourorderand brought us our food promptly.
Organization The nonprofitorganizationworked to provide aid to those in need.
Orientation The new employees received anorientationto the company’s policies and procedures.
Originality The artist’s work was praised for itsoriginalityand creativity.
Outcome Theoutcomeof the experiment was unexpected and surprising.
Outrage The community expressedoutrageat the injustice committed against the victim.
Outset The project faced challenges from theoutsetbut was ultimately successful.
Ownership The company claimedownershipof the intellectual property rights to the software.

Related:Abstract Nouns

Positive Nouns That Start with O

Noun Examples
Oasis Theoasisprovided a much-needed refuge from the desert heat.
Oblivion He drank tooblivionand forgot all his problems.
Obsession Hisobsessionwith fitness led him to become a personal trainer.
Occasion The wedding was a joyousoccasionfor all who attended.
Ocean Theoceanwas calm and peaceful, with the sun setting over it.
Odyssey The epicOdysseytook the hero through many trials and tribulations.
Offering The church collectedofferingsto support the local community.
Offspring The proud parents showed off theiroffspringto all their friends.
Omega Theomegarepresents the end of something and the beginning of something else.
Oneness The philosophy of yoga emphasizes theonenessof body and mind.
Opal She wore a beautifulopalnecklace that sparkled in the light.
Openness The company’s culture encouragedopennessand honesty among its employees.
Opulence The hotel was known for itsopulenceand luxury amenities.
Oracle Theoraclepredicted that the king would be victorious in battle.
Orbit The satellite was placed in a geostationaryorbitaround the earth.
Order The judge issued anorderfor the defendant to pay restitution to the victim.
Orgasm The couple experienced intense pleasure during their simultaneousorgasm.
Origin Theoriginof the universe is a subject of great scientific debate.
Ornament The Christmas tree was adorned with beautifulornamentsand lights.
Ovation The audience gave the performer a standingovationfor his outstanding performance.
Overcomer The cancer patient was anovercomerwho refused to let the disease beat her.
Overflow The river experienced anoverflowduring the heavy rain, causing flooding in the nearby areas.
Overjoyment The young child was filled withoverjoymenton Christmas morning.
Ownership Theownershipof the company changed hands after a hostile takeover.
Oxymoron “Jumbo shrimp” is an example of anoxymoron,使用两种截然相反的词在去哪里her.

Proper Nouns That Start with O

  • Obama
  • Ohio
  • Oklahoma
  • Olympus
  • Oman
  • Oprah
  • Orange County
  • Oregon
  • Orlando
  • Osaka
  • Oslo
  • Oxford
  • Oxfam
  • Oreo
  • Oakley
  • Oakland
  • Occidental College
  • Ocean City
  • Ocean Spray
  • Oceania
  • Odyssey
  • Othello
  • Ozark
  • Ozaukee County
  • Ozzy Osbourne

List of Nouns that Start with O

  • Oak
  • Oasis
  • Oath
  • Oathe
  • Oatmeal
  • Obedience
  • Obelisk
  • Obesity
  • Object
  • Objectification
  • Objection
  • Objective
  • Objectivity
  • Objector
  • Obligation
  • Oblige
  • Obliteration
  • Oblivion
  • Oboist
  • Obscenity
  • Obscurity
  • Observance
  • Observation
  • Observer
  • Obsession
  • Obsidian
  • Obstacle
  • Obstructionist
  • Obverse
  • Ocarina
  • Occasion
  • Occlusion
  • Occupancy
  • Occupant
  • Occupation
  • Occurrence
  • Ocean
  • Oceanography
  • Ocelot
  • Ocher
  • Ochre
  • Octahedron
  • Octoroon
  • Odor
  • Odyssey
  • Oep
  • Offal
  • Offender
  • Offense
  • Offer
  • Offering
  • Offersey
  • Office
  • Officer
  • Official
  • Officialdom
  • Offing
  • Offspring
  • Ohio
  • Oil
  • Oilcloth
  • Oilheating
  • Oilseed
  • Ointment
  • Oiticica
  • Okra
  • Oleomargarine olive
  • Ome
  • Omelet
  • Omen
  • Omission
  • Ommission
  • Omnipotence
  • Oneupmanship
  • Onion
  • Onlooker
  • Onrush
  • Onset
  • Onslaught
  • Ooh
  • Ooze
  • Open
  • Opener
  • Opening
  • Opera
  • Operand
  • Operation
  • Operator
  • Operetta
  • Opinion
  • Opium
  • Opponent
  • Opportunism
  • Opportunity
  • Opposite
  • Opposition
  • Oppression
  • Opprobrium
  • Optimality
  • Optimism
  • Optimization
  • Optimum
  • Option
  • Oracle
  • Oration
  • Orator
  • Oratorio
  • Oratory
  • Orb
  • Orbit
  • Orchard
  • Orchestra
  • Orchestration
  • Ordeal
  • Order
  • Ordering
  • Orderly
  • Ordinance
  • Ordinary
  • Ordnance
  • Organ
  • Organdy
  • Organification
  • Organism
  • Organist
  • Organization
  • Orgasm
  • Orgone
  • Orgy
  • Orientation
  • Origin
  • Original
  • Originality
  • Origination
  • Ornament
  • Ornamentation
  • Orphan
  • Orphanage
  • Orthicon
  • Orthodontist
  • Orthography
  • Orthophosphate
  • Oscillation
  • 振荡器
  • Osmium
  • Ossification
  • Ostracism
  • Otter
  • Ounce
  • Ouster
  • Outback
  • Outbreak
  • Outburst
  • Outcast
  • Outcome
  • Outcry
  • Outfield
  • Outfielder
  • Outfit
  • Outflow
  • Outgrowth
  • Outhouse
  • Outing
  • Outlaw
  • Outlawry
  • Outlay
  • Outlet
  • Outline
  • Outlook
  • Outpatient
  • Outpost
  • Outpouring
  • Output
  • Outrage
  • Outreach
  • Outset
  • Outside
  • Outsider
  • Oval
  • Ovation
  • Oven
  • Overall
  • Overcast
  • Overcoat
  • Overcrowding
  • Overestimation
  • Overexploitation
  • Overflow
  • Overhang
  • Overhaul
  • Overhauling
  • Overhead
  • Overheating
  • Overlay
  • Overload
  • Overnight
  • Overpayment
  • Overpopulation
  • Overpressure
  • Overprotection
  • Overriding
  • Overrun
  • Overseer
  • Oversight
  • Oversimplification
  • Overthrow
  • Overtime
  • Overture
  • Overweight
  • Owl
  • Owner
  • Ownership
  • Owning
  • Oxalate
  • Oxcart
  • Oxen
  • Oxidation
  • Oxide
  • Oxygen
  • Oxytetracycline
  • Oyster
  • Ozone

Nouns that Start with O with Meanings


Obviously, nouns that start with O come in many different shapes and sizes. Oak is a short three-letter word and is the name of a tree. Not only that but the noun can be used to describe the wood from an oak tree as well.


Music buffs, we are not talking about the band Oasis, although, that is a noun too. The oasis that’s being referred to here is a fertile area in a dry region. Those who find such places often never want to leave because they’re beautiful, calming, and relaxing.


Ohio is only one of fifty states in the United States. It isn’t a small spot, either, so you’ve likely heard the name before. Research reveals that Ohio features an area of 44,825 square miles. It was home to a population of 11.80 million in 2020. However, that number very well could have increased by now, and why wouldn’t it have? People flock to this location for reasons like the weather, the Pro Football Hall of Fame, and the Rock and Roll Hall of Fame.


Next up on this list of nouns that start with O is the word office. An office is a place where people go to perform work duties. This is usually at a location other than their houses, but those who have remote jobs sometimes have home offices as well.


The okra plant creates long edible beaked pods. This type of food can be eaten alone, as some people enjoy it fried. Meanwhile, others add okra to dishes such as gumbo or vegetable stew.

Some Last Thoughts

So, as you can see, there are plenty of nouns that start with O. The ones listed here barely even begin to scratch the surface. If you want to learn about others, type in a few keywords and perform a Google search. Or are you not about technology? That’s fine. Head to the library or get out that dusty dictionary on the bookshelf and see what you can find.

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Last Updated on April 19, 2023

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