Thomas Butler, 6th Viscount Ikerrin (1683 – 7 March 1719) was an Irish nobleman, born in Kilkenny, Ireland to James Butler, 3rd Viscount Ikerrin and Eleanor Redman, daughter of Colonel Daniel Redman, of Ballylinch, County Kilkenny. He was a descendant of John Butler of Clonamicklon. Thomas was a member of the clergy and Chaplain-General to the Army in Flanders. He married Margaret Hamilton, daughter of James Hamilton of Bangor, County Down and Sophia Mordaunt. His elder brother Pierce Butler, 4th Viscount Ikerrin, a Brigadier general in the Army, died in 1711, leaving a young son, James, who succeeded as 5th Viscount but died young, whereupon Thomas succeeded to the title.