Omicron (Ο or ο) is the 15th letter of the Greek alphabet.

Omicron, Omikron, Ο or ο may also refer to:

Science SARS-CoV-2 Omicron variant, a variant of the virus that causes COVID-19 Omicron (wasp), a genus of wasps Polynucleobacter necessarius, a bacterium originally designated as Omicron (German: )

Other uses ο, , , the number 70 in ancient, Byzantine and modern Greek numerals Omicron (film), a 1963 Italian film Omicron Hill, a summit in Alaska, US Omikron: The Nomad Soul, an adventure video game

See also

Omikronpapillomavirus, a genus of viruses

(omicron) (omicron) O (disambiguation) Omnicron (disambiguation)