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