W12 may refer to:
Automobiles McCormick W-12, a farm tractor Mercedes-AMG F1 W12 E Performance, a Formula 1 car Volkswagen W12, a concept car Volkswagen W-12, its engine
Other uses Amangu language British NVC community W12, a woodland community in the British National Vegetation Classification system Cierva W.11 Air Horse, a British helicopter proposal Hansa-Brandenburg W.12, a fighter floatplane Icosidodecahedron London Buses route W12 W12 engine, a twelve-cylinder engine Volkswagen Group W-12 engine W12 nuclear warhead, an American nuclear weapon design West 12, a shopping centre in London W12, a postcode district in London, England