W9 may refer to:
Transportation Wizz Air UK (IATA code: W9) Air Bagan (former IATA code: W9), a former airline of Myanmar London Buses route W9, England
Other uses Form W-9, used by the US federal government for tax purposes W9, a postcode district in the W postcode area, England W9 (TV channel), a French television channel W9 (nuclear warhead), an American nuclear artillery shell Japanese minesweeper W-9, several ships Niland Geyser (scientific designation), California, US
See also 9W (disambiguation)