Sir William Blackett, 2nd Baronet of Newcastle-upon-Tyne (11 February 1690 – 25 September 1728), of Pilgrim Street, Newcastle-upon-Tyne and Wallington Hall, Northumberland, was a British landowner and Tory politician who sat in the House of Commons from 1710 to 1728. Blackett was the son of William Blackett and his wife Julia Conyers. He was educated at University College, Oxford. On the death of his father in 1705, he succeeded to the baronetcy and to Wallington Hall, Cambo. Blackett was a Jacobite but toned down his support after a warrant was issued for his arrest.