Omo or OMO may refer to:

• the IATA airport code for Mostar International Airport
• Omo River in southern Ethiopia 
• Omo Remains - collection of hominid bones
• Omo National Park in Ethiopia
• Open market operations by the Federal Reserve or other central banks
• Open Market Option allows someone approaching retirement to ‘shop around’
• Oracle Media Objects a software development application.
• Omo (detergent) - a detergent product
• Omo - a historical site in Louisiana, U.S.A.
• Omo - a Greek word for the scapula, although the omohyoid muscle consist of the same word
• One-man operation (OMO), a bus or tram on which the driver collects the fares as well as drivingobscure/fan acronym
• Ontario Mathematics Olympiad

Omo or OMO may refer to:

• Omo remains, a collection of hominid bones
• Omo River in southern Ethiopia
• Omø, an island in Denmark
• Omo National Park, in Ethiopia
• Open market operations, by the Federal Reserve or other central banks
• Omo (detergent), a detergent product
• Ontario Mathematics Olympiad
• Omo Osaghae (born 1988), American hurdler
• Suleiman Omo (born 1985), Nigerian footballer for various clubs in southeastern Europe

Omø is a Danish island in the Great Belt. The island covers an area of , with a 12-kilometre (7-mile) coastline, and has 168 inhabitants, of which the majority inhabit Omø village, which has a church, and Kirkehavn, a small harbour with a ferry boat berth, along with a newly built marina, made for the purpose of promoting fishery, which, along with agriculture, conforms the island's main economic activity. Some of the island's natural features are its lake and its bog; also, it is characterized for its varied bird life.