FID

FID or fid may refer to:
 * Elizabeth Field (Suffolk County, New York), US, IATA code
 * Fid, a hollow spike for use in ropework
 * The Fid, a mountain in Antarctica
 * F.I.D. (album), by Masami Akita
 * FID, the country code used by FIDE
 * Financial institutions duty, an Australian tax
 * Flame ionization detector
 * Flight initiation distance
 * Foreign internal defense
 * Free induction decay
 * Fréchet inception distance, image quality metric
 * International Federation for Information and Documentation
 * Focus-image distance in projectional radiography
 * Stop the Decline (Italian: Fermare il Declino), an Italian political party