FMO

FMO may refer to:
 * Fenna-Matthews-Olson complex
 * Fish Marketing Organisation, a statutory body of Hong Kong
 * Flavin-containing monooxygenase
 * Flexible macroblock ordering
 * Fragment molecular orbital
 * Frontier molecular orbital theory
 * Münster Osnabrück Airport in North Rhine-Westphalia, Germany
 * Netherlands Development Finance Company (Dutch: Nederlandse Financierings-Maatschappij voor Ontwikkelingslanden N.V.)