Daniel O'Brien, 3rd Viscount Clare (died 1691), was with King Charles II in exile during the interregnum.

At the Glorious Revolution he supported James II, sitting in the Patriot Parliament and fighting for him at the Battle of the Boyne.

His father's family was the senior branch of the O'Briens, a Gaelic Irish dynasty that descended from Brian Boru, medieval high king of Ireland.

[9] His grandfather died in 1663[10] or in 1666, and his father succeed as 2nd Viscount and he gained the courtesy title of Baron Moyarta.

[16] During the War of the Two Kings, Clare served with the Jacobite Irish Army loyal to James II.

He was the colonel of Clare's Dragoons, which he led against William of Orange at the Battle of the Boyne (1 July 1690) and was later exiled in France as part of the Flight of the Wild Geese.