Henry Joseph Clarke (July 7, 1833-September 13, 1889), who sometimes used the middle names Hynes and O'Connell, was a lawyer and Manitoba politician.

Born in Donegal (now in the Republic of Ireland) on July 7, 1833, Clarke moved with his family to Canada at age three. He practiced law in Montreal before moving to California during the "gold rush" of 1858, also living in El Salvador for a period in the early 1860s. He then returned to Montreal and developed a strong reputation as a criminal lawyer. Clarke ran for parliament as a Liberal-Conservative in the election of 1863, losing to Liberal Finance Minister Luther Hamilton Holton in the riding of Chateauguay. In 1867, he wrote a short biography of fellow Irish Catholic politician Thomas D'Arcy McGee.

On the advice of George-Etienne Cartier and Bishop Alexandre-Antonin Tache , Clarke moved to Manitoba in 1870 to assist in the establishment of a provincial government. He was elected by acclamation for the riding of St. Charles in Manitoba's first general election (December 27, 1870), and was appointed as the province's first Attorney-General on January 3, 1871. In this capacity, he took a lead role in establishing the province's legal system.

Clarke had a poor personal relationship with Lt. Governors Adams George Archibald (1870-1872) and Alexander Morris (1872-1877), who considered him intemperate and unduly ambitious (they believed, correctly, that Clarke wanted to establish personal authority over the Manitoba bar). In spite of this, Clarke was appointed as a representative to Ottawa for an 1871 conference on immigration, and to an 1873 meeting on "better terms".

Clarke was a political spokesman for those members of Manitoba's Métis community who opposed the leadership of Louis Riel. He was thus opposed by both "ultra-loyalists" among the English and by Riel's more numerous supporters among the Métis. He frequently clashed with fellow cabinet-member Joseph Royal , the political spokesman for the latter group. In the Canadian general election of 1872, Clarke stood against Riel in the riding of Provencher -- however, both candidates resigned to allow the acclamation of George-Etienne Cartier following the latter's defeat in Montreal.

Clarke is sometimes listed as the third Premier of Manitoba, but this is inaccurate. Like his "predecessors" Alfred Boyd and Marc-Amable Girard, Clarke was simply a leaing minister in a cabinet controlled by the province's Lt. Governors. Morris, in fact, rejected Clarke's request to be recognized as Premier in 1873. Some modern sources list Clarke as having been the "Chief Minister" of Manitoba from 1872 to 1874, but he was not described by this title at the time; the term appears to be a more recent invention. Clarke was, however, acknowledged as the government leader in the legislature.

The ministry which included Clarke was defeated in July 1874, following John Norquay's unsuccessful attempt at electoral redistribution. Clarke resigned as Attorney General, and again moved to California. He returned to Winnipeg in 1877, and ran unsuccessfully for the riding of Rockwood in the provincial elections of 1878 and 1879. Previously a supporter of French language rights, Clarke was by this time campaigning against bilingualism and state funding for Catholic schools. Despite this, he later defended twenty five followers of Louis Riel in court, after the second Riel Rebellion of 1885.

Clarke died near Medicine Hat in 1889, while traveling by train.