William J. Brown may refer to:
William J. Brown (architect) (died 1970), American architect William J. Brown (boxing) (1874–1943), American boxing commissioner, referee, and promoter. William J. Brown (Indiana politician) (1805–1857), member of the Indiana House of Representatives William J. Brown (Ohio politician) (1940–1999), Ohio Attorney General William Jethro Brown (1868–1930), Australian jurist and professor of law
See also William Brown (disambiguation) William Joseph Browne (1897–1989), Canadian politician in the Newfoundland House of Assembly and the Canadian House of Commons