Viscount Shannon, in the County of Limerick, was a title in the Peerage of Ireland. It was created in 1660 for the Honourable Francis Boyle, fourth son of Richard Boyle, 1st Earl of Cork. He was succeeded by his grandson, the second Viscount. He was a Field Marshal in the Army and served as Commander-in-Chief of Ireland from 1727 to 1740. The title became extinct on his death in 1740. Title should have gone to his younest brother John Boyle (3rd Viscount Shannon).