William Henry Harrison Miller (September 6, 1840 – May 25, 1917) was an American lawyer and Attorney General of the United States.
Born in Augusta, New York, William Miller graduated from Hamilton College in 1861. While at Hamilton, he joined The Delta Upsilon Fraternity. He studied law in the office of Chief Justice Morrison Waite, and was admitted to the bar at Peru, Indiana in 1865. Miller practiced in that city for a short time, and also held the office of county school examiner. For many years, and particularly during the campaign of 1888, he was a confidential advisor to General Benjamin Harrison. In 1889, President Harrison appointed Miller Attorney General. He served in that capacity for the duration of Harrison's term, until 1893. Miller died in 1917 in Indianapolis, Indiana, and is buried in Crown Hill Cemetery in that city.