FSB may refer to:

in business and economics:

  • Financial Stability Board, an international group of financial authorities
  • Swedbank, a retail banking group
  • Fuqua School of Business, a business school
  • Federal savings bank, a class of bank in the United States
  • Federation of Small Businesses, a lobbying group of the United Kingdom
  • Financial Services Board (South Africa), a financial regulatory authority

in politics:

  • Federal Security Service (Russia), a domestic security service of Russia
  • Bolivian Socialist Falange, a political party of Bolivia
  • Trade Union Social Citizens List, a political group of Denmark

Other uses:

  • FSB (band), a bulgarian music band
  • Front-side bus, a computer subsystem
  • Fast Syndrome Based Hash, a group of cryptographic functions
  • Fire support base, a military encampment
  • Friends School of Baltimore, a Quaker institution
  • Brinjal fruit and shoot borer (Leucinodes orbonalis), a moth species
  • FSB or FB, an acronym for fire support base or fire base used by the U.S. military during the Vietnam War