William Godolphin, Marquess of Blandford (c. 1699 – 24 August 1731),[1] styled as Viscount Rialton until 1722, was an English nobleman and politician who sat in the House of Commons between 1720 and 1731.

[3] On 9 June 1720, Hugh Boscawen, the Member of Parliament for Penryn, was raised to the House of Lords as Viscount Falmouth.

[1] On 16 June 1722 Lord Rialton's maternal grandfather the Duke of Marlborough died, and was succeeded by his daughter Henrietta under a special Act of Parliament.

William Godolphin was now heir-apparent to his mother's dukedom as well as his father's earldom, and adopted the higher courtesy title of Marquess of Blandford.

Lady Blandford remarried on 1 June 1734, Harlington, Middlesex, the Tory MP Sir William Wyndham, as his second wife.

"According to Vicary Gibbs:[4] "Nature designed him for an excellent man, but the joviality of the times, his own social disposition, and the errors of his education led him astray."