William H. Illingworth, English-American photographer (d. 1893)

William H. Illingworth (20 September 1844 – 16 March 1893) was an English born photographer from St. Paul, Minnesota who accompanied both Captain James L. Fisk's 1866 expedition to the Montana Territory and Lt. Colonel George Custer's 1874 U.S. military expedition into the Black Hills of the Dakota Territory (now western South Dakota).