This is a Scottish locational surname. According to a dictionary of Scottish surnames, it originates from either of two small places called Garroch, one in the parish of Crossmichael and the other in the parish of Twynholm, both in the county of Kircudbrightshire. However we have not been able to identify either of these places unless one was formerly on the site of what is now Garroch House, three miles from New Galloway. There is also Garroch Head, a point on the isle of Bute, in the Firth of Clyde, which may also have produced nameholders but there are no known surname recordings which can definately be associated with that area, although that is not unusual. Locational surnames are much rarer in the Scottish and Irish Gaelic surname listings than patronymics. They were surnames usually given to people after they left their original homes to move somewhere else, and generally in search of work. In this case the earliest known recording that we have been able to prove positive is that of Mary Garroch, of the parish of Kirkcudbright in 1684, and a century later in 1790, that of Margaret Garroch at Wigtown.