Thomas Butler, 1st Baron Dunboyne (1271 â 9 October 1329) was the third son of Theobald Butler, 4th Chief Butler of Ireland and Joan FitzJohn.
He married Synolda le Petit, daughter of William le Petit
In 1324 he was called to the Irish Parliament (as were intermittently his descendants in the succeeding two centuries before the creation of the Barony of Dunboyne as a lordship of Parliament by patent 1541). He was created 1st Baron Dunboyne in 1324, by prescription. He fought in the Battle of Ardnocher on 9 October 1329 and was killed in action by the Chief of the Clan Geoghegan.