550 may refer to:
- 550, a year in the Common Era
- 550 (number), a number
- 550, the FTP error code meaning "Requested action not taken. File unavailable (e.g., file not found, no access)."
- 550 Music, a record label
- SIG SG 550, an assault rifle
- 550 cord, a type of parachute cord
- 550 Broad Street, an office building in Newark, New Jersey in the United States
- Radeon RX 550, a GPU designed by AMD
- New Balance 550, a shoe