IEO

IEO may refer to:

Independent Evaluation Office, of the World Bank International Economics Olympiad, an International Science Olympiad International English Olympiad, a competition conducted by the Science Olympiad Foundation Istituto Europeo di Oncologia, the European Institute of Oncology Interior-Earth object or Atira asteroid Institut d'Estudis Occitans (Institute of Western Studies), a cultural organization Initial exchange offering