OMB

OMB may refer to:


 * East Ambae language (ISO 639-3 code: omb), an Oceanic language spoken on Ambae, Vanuatu
 * Office of Management and Budget, the largest office within the Executive Office of the President of the United States
 * Olympiade Mathématique Belge, a mathematical competition for students in grades 7 to 12
 * OMB, a graphic design studio founded by Oscar Mariné
 * Ontario Municipal Board, an independent administrative board in the province of Ontario, Canada
 * Optical Media Board, a national agency under the Office of the President of the Philippines
 * Oregon Marching Band, the marching band of the University of Oregon
 * Oregon Medical Board, state agency responsible for establishing the rules and regulations for medicine