Richard Butler, 5th Viscount Mountgarret (died 27 February 1707) was an Irish soldier and politician.
A devout Roman Catholic, he was imprisoned for his faith in Liverpool in 1658 under The Protectorate.
In 1689, he was summoned to the Irish House of Lords by James II of England in the brief Patriot Parliament.
[1] He raised a regiment, of which he was colonel, in support of James II in the Williamite War in Ireland.
He refused to take the Oath of Supremacy when attending the Irish House of Lords in 1692, but in 1697 he secured a reversal of the outlawry passed against his grandfather, Richard Butler.