FSU may refer to:
Universities Fairmont State University, West Virginia Fayetteville State University, North Carolina Ferris State University, Michigan Fitchburg State University, Massachusetts Florida State University, a large public research university in Tallahassee, Florida Framingham State University, Massachusetts Frostburg State University, Maryland University of Jena, (), Thuringia, Germany California State University, Fresno, which brands itself as Fresno State University
Trade unions Fédération Syndicale Unitaire, French trade union, largest in the public sector Finance Sector Union, Australian trade union Financial Services Union, Irish trade union
Other uses Floating storage unit, a statically moored vessel used for temporary storage, (e.g. oil). Former Soviet Union, collective term for the fifteen countries that formed the Soviet Union until 1991 Free Speech Union, British organisation founded in 2020 Free Speech Union (New Zealand), New Zealand group founded as the Free Speech Coalition in 2018, renamed to Free Speech Union in 2021 Friends Stand United, street gang Fuse-Switch-Unit, opposite of SFU, relating to the order an electrical fuse is inserted in a circuit