William Henry Draper (March 11, 1801 – November 3, 1877) was a lawyer, judge, and politician in Upper Canada, later Canada West.

He was born near London, England, in 1801, the son of Rev. Henry Draper and Mary Louisa. He joined the East India Company at age 15 and made at least two voyages to India.

In 1820, he settled in Port Hope, Upper Canada. Draper married Augusta "Mary" White in York, Upper Canada, in 1826^[1] with whom he had several children, including William George Draper and Francis Collier Draper, both of whom were well-known lawyers; the latter also served as chief of police in Toronto.

He died in Yorkville (now part of Toronto) in 1877.

In 1822, he started to study law under Thomas Ward in Port Hope. He then moved to Cobourg and finished his articles in the office of George Strange Boulton. In 1828, Draper was called to the bar of the Law Society of Upper Canada. In 1829, he secured a position in the office of John Beverley Robinson and then partnered with Solicitor General Christopher Alexander Hagerman.

He was elected to the 13th Parliament of Upper Canada and represented Toronto in 1836. Later that year, he was appointed to the Executive Council and the following year became solicitor general. Draper handled many of the prosecutions following the Upper Canada Rebellion of 1837.

By 1839, he had broken with his Family Compact friends and set his political goal: "To found a party on a larger basis than ever had been formed before." In 1840, he became attorney general for Upper Canada. Draper supported the union of Upper and Lower Canada on economic grounds and also believed that because the British government favoured the union, it would be better to participate in the process than to criticize it from the sidelines. He was elected to the 1st Parliament of the United Canadas as a moderate conservative and continued as attorney general for Canada West, a member of the Executive Council, and a co-leader of the government in the Assembly along with the moderate liberal Samuel Harrison. Although his first attempts to establish a conservative alliance with French Canadians failed, Draper played an important role in enabling Louis-Hippolyte Lafontaine to take office in 1842, even at the cost of resigning himself and of seeing Robert Baldwin succeed him as attorney general for Canada West.

Draper resumed leading the government 13 December 1843 jointly with Denis-Benjamin Viger. At the next election, in 1844, the supporters of Draper, Viger and Governor Charles Metcalfe, including the young John A. Macdonald, won a majority. He continued as government leader until 1847. During this period, legislation was passed dealing with schools in both Canada East and Canada West, byr Draper's attempt to establish a University of Upper Canada failed. Draper helped Macdonald gain recognition by naming him to a cabinet post.

In 1847, with the arrival of Lord Elgin, Draper resigned from the position of attorney general and became a judge of the Court of Queen's Bench. In 1856, he became chief justice of the Court of Common Pleas of Upper Canada, and in 1869, he became chief justice of the Court of Error and Appeal in Ontario.