9Y or 9-Y may refer to:
9 years 9Y, IATA airline code for Air Kazakhstan, which went bankrupt in 2004 9Y, international code identifying airplanes from the state of Trinidad and Tobago Salmson 9Y, a model of Salmson 9 USP9Y, or Ubiquitin specific peptidase 9, Y-linked 9Y, Aircraft registration for Trinidad and Tobago
See also Y9 (disambiguation)