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Words Starting With O
All 397 English words beginning with O, from 2 to 14 letters, grouped by length with the longest and most useful highlighted.
Key facts about this word list
- Words in this list
- 397
- Word lengths
- 2–14 letters
- Most common length
- 8 letters (69)
- Shortest
- od, oe, of
- Longest
- organizational
8-letter words are the largest group here — 69 words, 17% of the list.
The longest entry is “organizational” (14 letters); the shortest are “od”, “oe”, “of”.
The most frequently used are “of”, “on”, “or”, “our”, “one”.
397 wordsshowing 302
2-letter words (10 of 13)
- od
- oe
- of
- oh
- oi
- ok
- om
- on
- op
- or
3-letter words (17 of 22)
- oak
- obj
- och
- odd
- ode
- off
- ohm
- oil
- old
- ole
- one
- ooh
- opp
- opt
- orb
- ore
- org
4-letter words (29 of 38)
- oaks
- oath
- obey
- odds
- odor
- offs
- ohio
- oils
- okay
- olds
- oman
- omar
- omit
- omni
- once
- ones
- only
- onto
- onyx
- oops
- opal
- open
- opus
- oral
- orgy
- orig
- oslo
- otis
- otto
5-letter words (27 of 36)
- oasis
- obese
- occur
- ocean
- octet
- offer
- often
- older
- olive
- olson
- omaha
- omega
- onion
- onset
- opens
- opera
- opted
- optic
- orbit
- order
- organ
- orion
- ortho
- osaka
- oscar
- other
- otter
6-letter words (37 of 49)
- object
- obtain
- occult
- occupy
- occurs
- oceans
- octave
- odessa
- offers
- office
- offset
- oldest
- oldies
- oliver
- olivia
- onions
- online
- opaque
- opened
- opener
- openly
- oppose
- optics
- option
- oracle
- orange
- orchid
- orders
- oregon
- organs
- orgasm
- orgies
- orient
- origin
- orphan
- others
- ottawa
7-letter words (48 of 64)
- oakland
- oakwood
- obesity
- objects
- obliged
- oblique
- obscene
- obscure
- observe
- obvious
- oceania
- oceanic
- october
- odyssey
- offence
- offense
- offered
- officer
- offices
- offline
- olivier
- olympia
- olympic
- olympus
- omitted
- onboard
- oneself
- ongoing
- ontario
- onwards
- opening
- operate
- opinion
- opposed
- optical
- optimal
- optimum
- options
- orbital
- orchard
- ordered
- organic
- orgasms
- origins
- orioles
- orlando
- orleans
- ottoman
8-letter words (52 of 69)
- obituary
- observed
- observer
- obsessed
- obsolete
- obstacle
- obtained
- occasion
- occupied
- occurred
- offences
- offended
- offender
- offenses
- offering
- officers
- official
- offshore
- oklahoma
- olympics
- omission
- oncology
- ontology
- openings
- openness
- operated
- operates
- operator
- opinions
- opponent
- opposing
- opposite
- optimism
- optimize
- optional
- ordering
- ordinary
- organise
- organism
- organize
- oriental
- oriented
- original
- ornament
- orthodox
- outbound
- outbreak
- outcomes
- outdated
- outdoors
- outgoing
- outlined
9-letter words (34 of 45)
- obedience
- objection
- objective
- obligated
- observers
- observing
- obsession
- obstacles
- obtaining
- obviously
- occasions
- occupancy
- occurring
- offenders
- offensive
- offerings
- officials
- offspring
- ombudsman
- omissions
- operating
- operation
- operative
- operators
- opponents
- optimized
- orchestra
- ordinance
- ordinator
- organised
- organisms
- organized
- organizer
- originals
10-letter words (24 of 32)
- obituaries
- objections
- objectives
- obligation
- obstetrics
- occasional
- occupation
- occurrence
- officially
- oldsmobile
- operations
- opposition
- oppression
- optimistic
- optimizing
- optionally
- ordinances
- ordination
- organising
- organizers
- organizing
- originally
- originated
- originator
11-letter words (11 of 14)
- obligations
- observation
- observatory
- obstruction
- occupations
- occurrences
- operational
- opportunity
- orientation
- originating
- outstanding
12-letter words (6 of 8)
- observations
- occasionally
- occupational
- optimization
- organisation
- organization
13-letter words (5)
- objectionable
- ophthalmology
- opportunities
- optimizations
- organizations
14-letter words (2)
- organisational
- organizational
Showing 302 of 397 words — 95 more available.
When this list helps
- Fill a crossword answer whose first letter is already O
- Open a word game with a O tile on the board
- Build an alliteration or vocabulary list around O
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Frequently asked questions
How many words start with O?
397 words in our 16,750-word English dictionary begin with O, and 69 of thems are 8 letters long. Larger unabridged dictionaries include more rare and technical entries.
What is the longest word starting with O in this list?
“organizational”, at 14 letters. The shortest are od, oe, of.
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