Daniel O'Brien, 4th Viscount Clare (died 1693) was the son of Daniel O'Brien, 3rd Viscount Clare and Philadelphia Lennard.
A Jacobite supporter of James II, he served with the Irish Army during the War of the Two Kings.
He was commander of a regiment[1][2] which he conveyed to France where he fought in the Battle of Marsaglia on 4 October 1693 and was mortally wounded.
Daniel O'Brien never married and was therefore succeeded by his brother Charles O'Brien, 5th Viscount Clare.
This biography of a viscount or viscountess in the Peerage of Ireland is a stub.