We don’t mean to be obscene or obnoxious, but we are convinced that this is the world’s most useful list of adjectives that start with O!

These words can be used when you are playing a game, describing a person, writing a story, complimenting someone, poem or social media post or simply expanding your vocabulary.

There are many adjectives that begin with O in the English language and we have gathered all of the useful ones right here for you to pick from.

The letter O is a particularly common one and is used in a number of prefixes as well. We hope that you enjoy these descriptive words that start with O and that you are able to find exactly what you are looking for.

Included here are:

Adjectives Beginning With O

adjectives that start with O

  • oafish
  • obedient
  • obese
  • objectionable
  • objective
  • obligatory
  • obliging
  • oblique
  • oblivious
  • oblong
  • obnoxious
  • obscene
  • obscure
  • observable
  • observant
  • obsessive
  • obsolete
  • obstinate
  • obstructive
  • obtainable
  • obtrusive
  • obtuse
  • obvious
  • occasional
  • occupational
  • occupied
  • oceanic
  • odd
  • odd-looking
  • odiferous
  • odious
  • odorless
  • odorous
  • offbeat
  • offensive
  • offhanded
  • official
  • officious
  • oily
  • OK
  • okay
  • old
  • older
  • oldest
  • adjectives that start with E
  • old-fashioned
  • ominous
  • omniscient
  • omnivorous
  • one
  • one-hour
  • onerous
  • one-sided
  • only
  • opaque
  • open
  • opened
  • openhanded
  • openhearted
  • opening
  • open-minded
  • operable
  • operatic
  • operational
  • operative
  • opinionated
  • opportune
  • opportunistic
  • opposable
  • opposed
  • opposing
  • opposite
  • oppressive
  • optimal
  • optimistic
  • optional
  • opulent
  • oral
  • orange
  • orangish
  • ordinary
  • organic
  • organizational
  • original
  • ornamental
  • ornate
  • ornery
  • orphaned
  • orthopedic
  • ostentatious
  • other
  • otherwise
  • our
  • outer
  • outermost
  • outgoing
  • outlandish
  • outraged
  • outrageous
  • adjectives that start with A
  • outside
  • outspoken
  • outstanding
  • outward
  • oval
  • overactive
  • overaggressive
  • overall
  • overambitious
  • over-assertive
  • overbearing
  • overcast
  • overcautious
  • overconfident
  • overcooked
  • overcritical
  • overcrowded
  • overemotional
  • overenthusiastic
  • overjoyed
  • overoptimistic
  • overpowering
  • overpriced
  • overprotective
  • overqualified
  • overrated
  • oversensitive
  • over sized
  • overt
  • overwhelmed
  • overwhelming
  • overworked
  • overwrought
  • overzealous
  • own

adjectives that begin with O

Adjectives That Start With O To Describe A Person

  • oafish
  • obedient
  • obese
  • objectionable
  • objective
  • obliging
  • oblivious
  • obnoxious
  • obscene
  • obscure
  • observant
  • obsessive
  • obstinate
  • occupied
  • odd
  • odd-looking
  • odiferous
  • odious
  • offensive
  • offhanded
  • officious
  • OK
  • okay
  • old
  • older
  • oldest
  • old-fashioned
  • ominous
  • omniscient
  • omnivorous
  • one
  • one-sided
  • only
  • openhearted
  • open-minded
  • opinionated
  • opportunistic
  • oppressive
  • adjectives that start with U
  • optimistic
  • opulent
  • ordinary
  • original
  • ornery
  • orphaned
  • ostentatious
  • outgoing
  • outlandish
  • outraged
  • outrageous
  • outspoken
  • outstanding
  • overactive
  • overaggressive
  • overambitious
  • over-assertive
  • overbearing
  • overcautious
  • overconfident
  • overcritical
  • overemotional
  • overenthusiastic
  • overjoyed
  • overoptimistic
  • overpowering
  • overprotective
  • overqualified
  • overrated
  • oversensitive
  • overwhelmed
  • overwhelming
  • overworked
  • overwrought
  • overzealous

Positive Adjectives That Start With O

  • objective
  • obliging
  • obtainable
  • omniscient
  • openhanded
  • openhearted
  • open-minded
  • opportune
  • optimal
  • optimistic
  • optional
  • opulent
  • organic
  • original
  • ornamental
  • ornate
  • outgoing
  • outstanding
  • overjoyed
  • adjectives that start with i

This collection of adjectives starting with O was carefully crafted to provide you with the best possible list that would include all of those which may actually be used in daily life or are common in writings, while not including those that are so uncommonly used that they would be pointless to add in to this list.

There are some O words to describe someone here that would be perfect for compliments or to include in holiday cards to friends and family.

For example, a person can be outstanding, open-minded, openhearted, optimistic and more.

Interestingly, there are actually quite a few negative O adjectives to describe a person. But we hope that you will mainly use this list to help build others up and make the world a better place!