Sir Antoine-Aimé Dorion, lawyer, politician, judge (born 17 January 1818 in Ste-Anne-de-la-Pérade, Lower Canada; died 31 May 1891 in Montréal, QC). A member of the Assembly of the Province of Canada 1854–61 and 1861–67, Dorion became a well-known Parti Rouge leader in the 1850s, praising American political institutions, supporting liberal ideas, promoting tariff reform and the colonization of virgin lands, and attacking financial and business interests as well as certain aspects of the Roman Catholic Church's presence in society.

In 1858, Clear Grit leader George Brown formed a short-lived government with Dorion as leader for Canada East. He was also attorney general (Canada East) in the John Sandfield Macdonald-Dorion ministry of 1863–64. Vigorously opposed to the Confederation project, however, he refused to adhere to the Great Coalition of 1864 that united Brown and the Clear Grits from Canada West with the Conservatives from both halves of the province. In November 1864, following the Québec Conference, he denounced the projected federation as a disguised legislative union that would accord virtually no autonomy to the provinces even in matters of local concern. He also insisted that the people should be consulted, since it was their interest and prosperity that were clearly at stake. For the next two years Dorion led Lower Canadian opposition to the proposals.

Following Confederation, Dorion sat in the House of Commons until 1874 and was briefly minister of justice and attorney general in the Liberal government of Alexander Mackenzie. In 1874 he was named chief justice of the Court of Queen's Bench of Québec.