Sir William Blackett, 2nd Baronet

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. He was elected Mayor of Newcastle for 1718–19.

Blackett was a Jacobite but toned down his support after a warrant was issued for his arrest.

He married Barbara Villiers, daughter of the Earl of Jersey, in 1725. They had no children, although he had previously had an illegitimate daughter, Elizabeth Orde; the baronetcy became extinct upon his death. He bequeathed his estates at Allendale, Northumberland and Wallington Hall, Cambo to his nephew Sir Walter Calverley, 2nd Baronet of Calverley, conditional upon the latter's marriage to Elizabeth Orde, Blackett's natural daughter and his change of name to Blackett; he implemented the change of name by a private act of Parliament, Calverley's Name Act 1733 (7 Geo. 2. c. 4 ).