CYS

CYS or Cys may refer to:

• Cysteine, an amino acid abbreviated Cys
• Cheyenne Regional Airport, Wyoming, United States, IATA and FAA LID airport code
• Cathays railway station, Cardiff, Wales, station code
• California Youth Symphony, a San Francisco Bay Area symphony orchestra for young musicians
• Cyprus Organization for Standardization, the Cyprus national standardization body
• Cys Kurland, footballer who played for the South African national side in 1947