Boytonrath is a townland in the barony of Middle Third (South Tipperary), Ireland. It is completely rural today and the nearest town is New Inn. It is also part of the Roman Catholic parish of New Inn & Knockgraffon in the Roman Catholic Archdiocese of Cashel and Emly. In the past though, it was a parish in its own right. It appears in early modern to 18th century records as having a considerable population, relative to the time.
The families most associated with Boytonrath are the Tobins and the Loughnanes (O'Loughlins). These have evidently dwelt here from at least the 17th century, and are listed as being the chief occupants of the of Middle Third (and almost certainly of Boytonrath) in William Petty's 1659 Down Survey.
One large farmhouse, which is still occupied (by Loughnanes), dates from the 1640s or before. Also present are the ruined foundations of a once impressive castle. Of considerable interest, too, is a small ruined church and its graveyard, which has several well preserved headstones erected by families still resident in the area (including O'Donnells, Loughnanes and Tobins) which date from the 1700s.
A branch of the Butler family were settled here in the seventeenth century, but following the Irish Rebellion of 1641 relocated to County Clare. Sir Theobald Butler, Solicitor General for Ireland to King James II, was its most celebrated member.