Dominick Sarsfield, 4th Viscount Sarsfield (died 1701) was an Irish aristocrat and supporter of the Jacobite cause during the Williamite War in Ireland. Part of a prominent Roman Catholic family of Old English descent (although the first Viscount was a Protestant) who owned lands in County Limerick and County Cork, Sarsfield was the son of and succeeded him following his death in 1687. His mother was Elizabeth de Courcy, daughter of Patrick de Courcy, 13th Baron Kingsale and Mary Fitzgerald, daughter of Sir John Fitzgerald of Dromana. He was married to Anne Sarsfield of Lucan, the sister of Patrick Sarsfield. His letters to Anne show evidence of a deep affection between the husband and wife.