Y5

Y5 may refer to:
 * a Chinese copy of the Soviet Antonov An-2
 * the abbreviation of "Year 5", the fifth year of study
 * Pace Airlines IATA code
 * Y-5 cusping pattern found in hominoid molars
 * LNER Class Y5, a class of British steam locomotives
 * Y5, a character in the animated series Adventure Time: Distant Lands episode "BMO"