Sir Oliver Mowat GCMG PC QC (July 22, 1820 – April 19, 1903) was a Canadian lawyer, politician, and Ontario Liberal Party leader. He served for nearly 24 years as the third premier of Ontario. He was the eighth lieutenant governor of Ontario and one of the Fathers of Confederation. He is best known for defending successfully the constitutional rights of the provinces in the face of the centralizing tendency of the national government as represented by his longtime Conservative adversary, John A. Macdonald. This longevity and power was due to his maneuvering to build a political base around Liberals, Catholics, trade unions, and anti-French-Canadian sentiment.[1]

Mowat was born in Kingston, Upper Canada (now Ontario), to John Mowat and Helen Levack, Scottish Presbyterians[2] who both emigrated from Caithness, Scotland.[3] As a youth, he had taken up arms with the loyalists during the Upper Canada Rebellion of 1837, which suggested a conservative inclination in politics. But he instead joined the Reformers.

Mowat was called to the bar of Upper Canada on November 5, 1841. In 1846, he married Jane Ewart, a daughter of John Ewart of Toronto. Mowat and his wife had three sons and four daughters. In 1856 Mowat was appointed Queen's Counsel.

He was known to be a tenacious legal practitioner, with two of his cases being upheld by the Judicial Committee of the Privy Council. In the 1858 case Bowes v. City of Toronto, John George Bowes (previously mayor of Toronto) was successfully sued for recovery of the share of the profit he was suspected to have made in collaboration with co-premier Francis Hincks out of a speculation in city debentures.[4] Afterwards, Mowat admitted, "I cannot speak with much force unless I have an opponent, and things are said by others which I do not altogether coincide with."

In the 1850s

Mowat first entered politics as an alderman of the City of Toronto in 1857. From there, he became a member of the Legislative Assembly of the Province of Canada for South Ontario. As a member of the Assembly from 1858 to 1867, he was closely associated with George Brown. Mowat served as Provincial Secretary (1858) and Postmaster-General (1863–1864) in the pre-Confederation governments of George Brown and John Sandfield Macdonald for the Liberal Party of Canada.

Mowat was a member of the Great Coalition government of 1864 and was a representative at that year's Quebec Conference, where he helped work out the division of powers between the federal and provincial governments. On November 14, 1864, he was appointed to the judiciary as Vice-Chancellor of the Court of Chancery of Upper Canada,[5] He held this position until he was appointed premier on October 25, 1872. One of the more notable cases during his time on the Court was Dickson v Burnham in 1868,[6] whose underlying jurisprudence would be altered during his later time as Premier, with the passage of the Rivers and Streams Act, 1884.[7]