OM or om may stand for:

• Observer Magazine, a supplement of the British Observer newspaper
• Odyssey of the Mind, an international problem-solving competition
• Olympique de Marseille, a prominent French football team
• Om, the most sacred syllable in Hinduism
• OM (Officine Meccaniche), which was an Italian truck manufacturer
• Oman, which has the country code OM
• OM HEX, which is a Swedish company that owns several Stock Exchanges in Northern Europe
• Order of Merit membership post-nominal letters in the British honours system