Example of English Proverbs Starting with the Letter 'O'

Oaks may fall when reeds stand the storm.
Of two evils choose the least.
Old birds are not caught with chaff.
Old friends and old wine are best.
Old is gold.
On Shank's mare.

Once bitten, twice shy.
Once is no rule (custom).
One beats the bush, and another catches the bird.
One chick keeps a hen busy.
One doctor makes work for another.
One drop of poison infects the whole tun of wine.

One fire drives out another.
One good turn deserves another.
One law for the rich, and another for the poor.
One lie makes many.
One link broken, the whole chain is broken.
One man's meat is another man's poison.
One man, no man.
One scabby sheep will mar a whole flock.
One swallow does not make a summer.
One today is worth two tomorrow.
Open not your door when the devil knocks.
Opinions differ.
Opportunity makes the thief.
Out of sight, out of mind.
Out of the frying-pan into the fire.