William H. McCullough (1901 – 17 December 1967), some times known as Billy McCullough, was a communist politician in Northern Ireland. McCullough became a trade unionist at an early age, initially in the National Union of Railwaymen, where he became branch secretary, then in the Amalgamated Engineering Union, where he was Belfast chairman, then in the National Association of Theatrical Television and Kine Employees, in which he was Irish area secretary.