ろ, in hiragana, or ロ in katakana, (romanised as ro) is one of the Japanese kana, each of which represents one mora.

The hiragana is written in one stroke, katakana in three.

Both represent [ɾo] ⓘ and both originate from the Chinese character 呂.

The Ainu language uses a small ㇿ to represent a final r sound after an o sound (オㇿ or).

The combination of an R-column kana letter with handakuten ゜ – ろ゚ in hiragana and ロ゚ in katakana – was introduced to represent [lo] in the early 20th century.