U+039F "Ο" Greek Capital Letter Omicron Unicode Character

Unicode Version 18.0

Ο
Source: Noto Sans Source: Browser Default

U+039F "Ο" Greek Capital Letter Omicron is the uppercase form of the fifteenth letter in the Greek alphabet, which holds a long and important history as the ancestor of the Latin letter "O" and is commonly used in modern Greek writing for the sound /o/. In mathematics and science, it often symbolizes the omicron function or concepts like the big O notation for asymptotic growth, though it can be easily confused with the visually identical Latin capital "O" in digital text. This character also gained public attention during the COVID-19 pandemic when the World Health Organization designated it as the name for the highly transmissible Omicron variant.

Encodings

HTML Decimal Encoding
Ο
HTML Hex Encoding
Ο
UTF-8 Encoding
0xCE 0x9F
UTF-16 Encoding
0x039F
UTF-32 Encoding
0x0000039F
C/C++/Java Escape
\u039f