Peter Samuel George Mackenzie (19 December 1862 – 1 November 1914) was a Canadian lawyer and politician.
His father, a cousin of the explorer Sir Alexander Mackenzie, was an agent of the company.
He was educated at Upper Canada College, Toronto, the High School of Montreal, the St. Francis College at Richmond, and McGill University Faculty of Law at Montreal graduating with a BCL, then articled in Montreal to Melbourne Tait and John Joseph Caldwell Abbott, the second of whom later became Prime Minister of Canada.
[1] On 4 February 1884 Mackenzie was called to the bar of Quebec and opened his own office at Richmond, later going into partnership with Henry Aylmer, who had been a member of the House of Commons from 1874 to 1878, and with Auguste-Maurice Tessier.
[1] He was a member of the governing body of Bishop's College[1] and in 1906 joined the Protestant Committee of the Council of Public Instruction.