FIRS

FIRS may refer to:


 * Federal Inland Revenue Service, the federal tax administrator in Nigeria
 * Fédération Internationale de Roller Sports, the International Federation of Roller Sports
 * FIRS (index), a share index of the Banja Luka Stock Exchange
 * Forensic Investigation Research Station, a "body farm" at Colorado Mesa University
 * Forum of International Respiratory Societies, a respiratory health advocacy organization