General Sir William Stewart (1643 – 4 June 1726), was a Scottish-born soldier, Commander-in-chief of Queen Anne's Forces in Ireland, Member of Parliament for County Waterford and a Privy Councillor.

Steuart himself was a first cousin of John Sinclair (d.1705), 8th Earl of Caithness, and a nephew of Lt.-Col. Sir Archibald Stewart (d.1689), the first Baronet of Burray.

His father had been granted lands in Ireland by Charles II of England in lieu of arrears of pay due to him as a Cavalier officer during the English Civil War, and it was there that William Steuart grew up.

Before Stewart took command, the regiment had taken part in aborted attempt to relieve the besieged city of Derry under another Colonel John Cunningham who was dismissed by King William for his failure.

He owned considerable amounts of land in Ireland that after his death was distributed between his nephews and nieces, the children of his deceased brother, James.

His nephews were: (1) Colonel John Steuart (d.1762) of Dublin, married Bridget Pocklington and inherited the General's land at Leighlinbridge, County Carlow, where his son, William (who married Anne, daughter of Sir Richard Butler, 5th Baronet), built Steuart/Stewart's Lodge in 1752; (2) Major Charles Stewart, who had a 'very considerable fortune of his own' bought Bailieborough Castle in 1724; and (3) James Steuart, Admiral of the Fleet, who was the executor of the General's will.

William Steuart (d.1736) of Ballylane, County Waterford, whose monument stands in Bath Abbey, was cut off with only a shilling.