Lady Elizabeth Dowdall (died 1658) was the daughter of Sir John Dowdall, a wealthy landowner in County Limerick Ireland.
In 1629, she married Sir Hardress Waller, who was later to become one of the regicides of Charles I.
In 1641, during the Irish Rebellion, Elizabeth successfully defended Kilfinny Castle against the rebels, and is reputed to have hung several of them during the fighting. She died in 1658.
One of her daughters was Elizabeth Waller, Baroness Shelburne, the wife of the economist Sir William Petty.