Colonel Thomas Butler of Kilcash (died 1738) was the son of Walter Butler of Garryricken and Lady Mary Plunket, only daughter of Christopher, 2nd Earl of Fingall. He succeeded to the estates of his grandfather - Richard Butler of Kilcash. He was Colonel of a regiment of foot in the Jacobite Irish Army of King James II.
In 1696, he married Lady Margaret Burke, eldest daughter of William, Earl of Clanricarde, widow of Bryan Magennis, Viscount Iveagh. She died at Kilcash 19 July 1744. They had three sons and five daughters.