Henry Allcock (baptised 26 January 1759 – 22 February 1808) was a judge and political figure in Upper and Lower Canada.
His family was from Edgbaston and he was born in Birmingham, England in 1759 and studied law at Lincoln's Inn in London.
In 1800, he was elected to the 3rd Parliament of Upper Canada representing Durham, Simcoe and 1st York.
In 1802, he became chief justice for Upper Canada succeeding John Elmsley and, in 1803, he was appointed to the Executive Council for the province.
In 1805, he became Chief Justice of Lower Canada and a member of the Executive Council of Lower Canada despite support for another candidate, Jonathan Sewell, by the upper class of the province and the lieutenant governor.