IOF may refer to: Fraunhofer IOF, the Fraunhofer Institute for Applied Optics and Precision Engineering Independent Order of Foresters Infraorbital foramen, an opening in the skull under the eye socket Institute of Forestry, a forestry-related technical institute under Tribhuvan University, Nepal's largest academic institution Institute of Frescography, an institute for fresco and mural art Chartered Institute of Fundraising International Orienteering Federation International Osteoporosis Foundation, a global alliance of organizations concerned with osteoporosis and metabolic bone disease Israeli Occupation Forces, an unofficial name widely used in Palestine and among pro-Palestinian groups in reference to the Israel Defense Forces