First found in County Clare, on the west coast of Ireland in the province of Munster, where they held a family seat from ancient times.
There are two distinct septs which make up this popular Irish name. The first is that from County Clare, who migrated South to County Waterford, circa 1400, and who were the hereditary poets to the O'Briens, Kings of All Ireland. The second sept were from County Donegal, where they were claimants to the ancient monastery lands of the area. In County Down the name has been transposed to MacGraw, and in Donegal it often appears as MacGragh. The original derivation is from the Gaelic "MacGraith", meaning "the son of Graith". Archbishop Miler McGrath, 1523 -1622, the former Franciscan friar, having become a Protestant, rose to be a Archbishop of Cashel, and in 1604 was twice married and held over seventy livings. One John Magrath took part in the 1798 Rising and was captured, but later escaped to America. His son, Andrew Condon Magrath (1813 - 1893), rose to become a distinguished judge, a Governor of Carolina, and a prominent Confederate in the American Civil War. The first recorded spelling of the family name is shown to be that of John McGraith, which was dated circa 1391, Author of "Caithreim Toirdhealbhaigh", during the reign of King Richard 11 of England, known as "Richard of Bordeaux", 1378 - Surnames became necessary when governments introduced personal taxation. In England this was known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.1399.
An Irish form of Gaelic Macrath (Macrae).