Richard Butler, 1st Viscount Mountgarret (1500 – 20 May 1571) was the son of Piers Butler, 8th Earl of Ormond and Lady Margaret Fitzgerald. He married his half first cousin Eleanor Butler, daughter of Theobald Butler of Polestown, the illegitimate brother of the 8th Earl of Ormond. He was created 1st Viscount Mountgarret in 1550.