What Is O in Morse Code?
The Morse code for O is ---, a sequence of 0 dots and 3 dashes. In international Morse code (the ITU standard), each letter has a unique combination of dots (·) and dashes (−). O is three dashes; combined with S (...) it forms the famous SOS distress signal.
When you hear or read “morse code o”, “morse code for o”, “o morse code”, or “letter o in morse code”, the answer is always the same 3-signal pattern: ---.
NATO Phonetic Word for O
In the NATO phonetic alphabet, the letter O is spoken as Oscar. This pairing — Morse code --- with the spoken word Oscar — is used by aviation, military, and amateur radio operators worldwide for unmistakable communication.
Practice: What Is the Morse Code for O?
Select the correct Morse code for O:
How to Tap Letter O in Morse Code
To transmit Letter O (---), use this sequence:
ITU Timing Rules
- Dot (·) = 1 unit
- Dash (−) = 3 units (3× longer)
- Signal gap = 1 unit
- Letter gap = 3 units
- Word gap = 7 units
Timing Reference Table
| Speed | Dot | Dash | Letter gap | Word gap |
|---|---|---|---|---|
| 5 wpm | 240ms | 720ms | 720ms | 1680ms |
| 10 wpm | 120ms | 360ms | 360ms | 840ms |
| 17 wpm (this page) | 70ms | 210ms | 210ms | 490ms |
| 20 wpm | 60ms | 180ms | 180ms | 420ms |
How to Remember Letter O in Morse Code
O for "OH-OH-OH" — three long dashes.
NATO phonetic word: Oscar — pair the spoken word with the rhythm to remember faster.
Frequently Asked Questions — Letter O in Morse Code
O in Morse code is ---. The letter O uses 0 dots and 3 dashes, the standard ITU pattern.
The Morse code for O is ---. Tap the 3 signals in sequence with a one-unit gap between each.
To send letter O: long press, then long press, then long press. The NATO phonetic name for O is Oscar.
--- means the letter O in international Morse code (the ITU standard used worldwide for amateur radio and communication).
The NATO phonetic alphabet word for O is Oscar. It pairs with the Morse code --- for clear voice and signal communication.
Related Morse Code Letters
Other letters often learned alongside O: