Organización Mundial del Comercio (Spanish for World Trade Organization)

Order of Minor Conventual (Franciscans)

Open Method of Coordination, a means of governance in the European Union

Outboard Marine Corporation

OMC (band), a New Zealand music group formerly known as Otara Millionaires Club

Old Man's Child, a Norwegian Black metal band

octyl methoxycinnamate, the active ingredient in sunscreens

Olifant Manufacturing Company of South Africa, now known as Land Systems OMC

Omnicom Group Inc. (stock symbol)