FSB may refer to:
Organizations Banking and finance Federal savings bank, a class of bank in the US Federation of Small Businesses, a British lobbying group Financial Services Board (South Africa), a financial regulatory authority Financial Stability Board, an international group of financial authorities First Somali Bank, a bank headquartered in Mogadishu, Somalia FöreningsSparbanken, former name of the retail banking group Swedbank
Schools Farmer School of Business, at Miami University, Ohio, US Friends School of Baltimore, a Quaker institution in Baltimore, US Fuqua School of Business, at Duke University, North Carolina, US
Other organizations Federal Security Service (Russian: ), the principal security agency of the Russian Federation Trade Union Social Citizens List (Danish: ), a Danish political group Bolivian Socialist Falange (Spanish: ), a Bolivian political party
Military Fire support base, a temporary military encampment Forward support battalion, a former unit of the US Army
Science and technology Brinjal fruit and shoot borer (Leucinodes orbonalis), a moth species Fast syndrome-based hash, cryptographic hash functions Front-side bus, a computer communication interface
Other uses FSB (band), a Bulgarian band Fellow of the Society of Biology, UK Fishbourne railway station (station code), in England Fortune Small Business, a defunct magazine