O (Armenian letter)

Օ, օ is the 36th and last letter of the Armenian alphabet. It represents the sound /o/, much like the letter "o" in the English word "orange". It is a relatively recent addition to the Armenian alphabet, having been introduced in the Middle Ages, likely to better represent loanwords from other languages. Prior to its introduction, the Armenian alphabet lacked a dedicated character for the /o/ sound.

The letter Օ is called "Ō" (o) in Armenian. In both uppercase (Օ) and lowercase (օ) forms, its shape resembles a slightly wider version of the Latin letter "O".

In Armenian dictionaries and texts, words beginning with Օ are typically found at the very end, following all words beginning with the other 35 letters of the alphabet. The frequency of Օ in native Armenian words is relatively low due to its later introduction and primary use in loanwords and specific proper nouns.