H12 may refer to:
Vehicles Bell H-12, an American utility helicopter Curtiss H-12, an American flying boat Hiller H-12, an American helicopter , a Royal Navy A-class destroyer , a Royal Navy H-class submarine LSWR H12 class, a British steam railcar
Other uses H-12, Islamabad, site of a campus of the National University of Sciences & Technology Highway H12 (Ukraine) London Buses route H12, a Transport for London contracted bus route