9O
# 9O

9O or 9-O may refer to:

* 9O, IATA code for National Airways Cameroon
* 9°, an abbreviation for ninth in some languages
   * Grêmio Atlético do 9° Regimento; see Grêmio Atlético Farroupilha
* 9O–9T, the ITU prefix codes for Democratic Republic of the Congo
* 9O, squadron code for No. 44 Maintenance Unit; see List of RAF Squadron Codes
