Sir William Stanley (1548 – 3 March 1630), son of Sir Rowland Stanley of Hooton (died 1612), was a member of the Stanley family. He was an officer and a recusant, who served under Elizabeth I of England and is most noted for his surrender of Deventer to the Spanish in 1587.
Stanley was educated with Dr. Standish at Lathom and was brought up in the Catholic faith. After school, he entered the service of his kinsman, Edward Stanley, 3rd Earl of Derby (c.1508–1572), and then served in the Netherlands as a volunteer under the Duke of Alba from 1567 to 1570. In 1570 he was sent on service to Ireland.
On the outbreak of the Second Desmond Rebellion in 1579, Stanley was promoted to captain under Sir William Drury, lord justice of Ireland, who knighted him at Waterford for his service in penetrating Limerick in pursuit of the followers of Gerald FitzGerald, 15th Earl of Desmond. He fought in the battle of Monasternenagh and defended the town of Adare. In 1580, he enlisted troops in England and led them to the rebellious province of Munster; but the new lord deputy, Lord Grey, quickly recalled him to the Pale to help put down the rebellion that had broken out in the vicinity of Dublin.
In 1581, he campaigned against the clans of Kavanagh and O'Toole, and on 30 August 1581 was commissioned to follow the lord deputy in the government's campaign against Fiach McHugh O'Byrne, a rebel leader whose fastness lay in the Wicklow mountains. During that campaign he was engaged at the Battle of Glenmalure in charge of the rear guard, and covered the retreat of Grey's forces after they had been routed from the glens. At the end of the year his troops were discharged, and he went to England to seek further employment from the queen's principal secretary, Lord Burghley.