Cognomen O'M (O'M 
) , across the world, is a very rare surname. The family name O'M is habitual in Colombia, where it is a very rare surname, Peru, where it is an extremely rare surname, and the United Kingdom. Not in comparison with a country's population, this name is the most popular in Latin America and the Caribbean, particularly Colombia, Mexico, and Peru. More frequently, O'M is the forename as well as the last name.