William McCullough

William McCullough may refer to:

• William McCullough (loyalist) (1949–1981), Northern Irish loyalist paramilitary with the Ulster Defence Association
• William McCullough (Northern Ireland politician) (1901-1967), Northern Irish communist and trade unionist
• William McCullough (New Zealand politician) (1843–1925), New Zealand politician
• Billy McCullough (1935–2026), Northern Irish footballer