• Fas receptor, an important cell surface receptor protein of the TNF receptor family known also as CD95, that induces apoptosis on binding Fas ligand.
• Fes, Morocco, the third largest city in Morocco, as an alternate spelling

FAS can stand for:

• Faculty of Architects and Surveyors now renamed the Architecture and Surveying Institute (United Kingdom).
• Faculty of Arts and Sciences at Harvard University
• Fatty acid synthase
• Federal Aid Highway System, roads built in the United States with funds provided by the federal government
• Federally assisted secondary road, roads built in the United States with funds provided by the federal government
• Federation of American Scientists, a non-profit organization formed in 1945 by scientists from the Manhattan Project
• Federation of Astronomical Societies, an international union of astronomical societies formed in 1974
• Femmes Africa Solidarité
• Ferrous Ammonium Sulfate (Mohr's Salt), a light green crystalline solid with the formula Fe(SO₄)₂(NH₄)₂.6H₂O (CAS number: 10045-89-3)
• Fetal Alcohol Syndrome, permanent and often devastating birth-defect syndromes caused by maternal overconsumption of alcohol during pregnancy
• Final Assembly (of manufactured products)
• Financial Accounting Standard, a standard determined by the Financial Accounting Standards Board
• Firsts and Seconds, a grade of hardwood lumber defined by the National Hardwood Lumber Association in the United States.
• Football Association of Singapore
• Foras Áiseanna Saothair, a state agency in the Republic of Ireland, with responsibility for assisting those seeking employment.
• Foreign Accent Syndrome, a rare medical condition whereby a person will switch to a different accent when speaking their own language, usually as a result of brain damage.
• Foreign Agricultural Service, the part of the United States Department of Agriculture that has primary responsibility for overseas programs
• Formability Analysis Software
• Free African Society, an 18th-century African-American community.
• Free Alongside Ship, an Incoterm
• Fuerzas Armadas de España, the Spanish Armed Forces
• Club Deportivo FAS, a Salvadoran football club

See also

• Fass