IEP may refer to:
Science and technology Immunoelectrophoresis, biochemistry method Inclusion–exclusion principle, in the mathematics branch of combinatorics Integrated electric propulsion, in marine propulsion Isoelectric point, the pH where a molecule is electrically neutral
Education and research Individualized Education Program, in the United States, for children with disabilities Instituts d'études politiques (Institutes of Political Studies), higher education institutions in France Institute for Economics and Peace, a think tank Institute for European Politics, a Berlin research centre Institute for Political Studies – Catholic University of Portugal () Internet Encyclopedia of Philosophy
Other uses Icahn Enterprises, an American conglomerate Independent Expert Panel, concerned with misconduct by members of the UK parliament Institute of Employability Professionals, a British professional association Intercity Express Programme, a British rail transport initiative Irish pound, the pre-euro currency of Ireland