Henry Cavendish, 2nd Duke of Newcastle upon Tyne, KG, PC (24 June 1630 – 26 July 1691), styled Lord Henry Cavendish until 1659 and Viscount Mansfield from 1659 to 1676, was an English politician.

After the Restoration of the Monarchy, he was appointed Master of the Robes (June 1660–62) and a Gentleman of the Bedchamber (1662–68).

[2] In 1676, he inherited the title of Duke of Newcastle and the family seats of Welbeck Abbey, Bolsover Castle and Nottingham Castle on the death of his father and was invested a Knight of the Garter in 1677.

He died in 1691, leaving no surviving male heir, and thus the dukedom became extinct.

Welbeck Abbey and other East Midlands estates passed to his favourite daughter Margaret, who had married John Holles, for whom the dukedom was recreated in 1694.