The letter O in Morse code is --- — — — —. O is the fourth most common letter in English, which is why it received a medium 3-signal code.
How to Translate O to Morse Code
To translate O to Morse code, write ---. In written form this is — — —. When sending by sound, tap a long beep then a long beep then a long beep. The dots and dashes follow the ITU-R M.1677-1 international Morse code standard used worldwide.
Visual Signal — What is O in Morse Code?
Here is what O looks like as physical signal blocks — this is the answer to "what is O in Morse code":
Memory trick: O is three dashes — three deep long sounds.
O in the NATO Phonetic Alphabet
In the NATO phonetic alphabet, O is called Oscar. When spelling out a word letter by letter on radio, operators say "Oscar" to make O unmistakable from other letters that sound similar.
Words Starting With O
Click any word to hear it in Morse code:
Frequently Asked Questions
What is O in Morse code? +
O in Morse code is ---, written as — — —. It uses 3 signals.
How do you translate O to Morse code? +
To translate O to Morse code, write ---. A dot is a short signal and a dash is three times as long.
Tap long then long then long — --- (— — —). The gap between signals within one letter is one dot length. The gap before the next letter is three dot lengths.
In the Two-Button Tap mode, press right then right then right for O. The input checks automatically when your tap count matches the code.
How Common is O in English?
O is the fourth most common letter in English. Morse code gave shorter codes to more frequent letters. O received a 3-signal code based on its frequency in everyday text.
Practice O in Morse
Start with the Learn page — O appears in a structured audio flashcard lesson. Then use practice mode for random drills. The timed quiz adds pressure that builds real recognition speed.