This surname ARMETT was of the locational group of surnames meaning one 'of Armitag' in County Staffordshire. The origin of the name was probably from the donation of land for 'building' by Richard de Rihill, sometime between 1211 and 1240 to the Knights Templars, an order instituted in 1118 and introduced into Yorkshire in 1152. The name meant 'the dweller at the Hermitage'. Local surnames, by far the largest group, derived from a place name where the man held land or from the place from which he had come, or where he actually lived. These local surnames were originally preceded by a preposition such as "de", "atte", "by" or "in". The names may derive from a manor held, from working in a religious dwelling or from literally living by a wood or marsh or by a stream. Most of the European surnames in countries such as England, Scotland and France were formed in the thirteenth and fourteenth centuries. The process had started somewhat earlier and had continued in some places into the 19th century, but the norm is that in the tenth and eleventh centuries people did not have surnames, whereas by the fifteenth century most of the population had acquired a second name.

Early records of the name mention ARMET (without surname) who appears in County Lancashire in the year 1185. Richard de Ermitage, 1259, County Chester, and Hugh del Herytage was recorded in the year 1296 in Warwickshire. Thomas Armitage appears in County Lancashire in 1300, and Willelmus del Ermytache et Agnes ux ejus was listed in the Yorkshire Poll Tax of 1379. A later instance of the name mention Joseph Armitage who married Mary Kedon at St, Dionis Backchurch, London in 1784.

The associated coat of arms is recorded in Sir Bernard Burkes General Armory. Ulster King of Arms in 1884.