William Herbert, 1st Baron Powis

William Herbert, 1st Baron Powis KB ( – 7 March 1655 ) was a Welsh politician who sat in the House of Commons at various times between 1597 and 1629.

Early life Herbert was born in Powis Castle, the son of Sir Edward Herbert (–1595) and the former Mary Stanley. In 1587, his father purchased the lands of the abeyant barony of Powis from their distant relative, Edward, an illegitimate son of the 3rd Baron Grey of Powis.

His maternal grandfather was Sir Thomas Stanley, who served as Under-Treasurer of the Royal Mint at the Tower of London during the reign of Queen Elizabeth I. In 1614, he was re-elected MP for Montgomeryshire and was re-elected in 1624, 1625, 1626 and 1628. He was created Baron Powis (a new creation) of Powis Castle on 2 April 1629. Marie Herbert (1604–1660), who married Humphrey Jones, son of Gruffyd Jones.

Lord Powis died on 7 March 1655.

In popular culture Herbert is a candidate for "Mr WH", the dedicatee of Shakespeare's sonnets.