The name is also found as Arnot (also Arnote, Arnocht, and Arnatt) and derives from the lands of Arnot in the Portmoak Parish, Kinross-shire where the family lived from the middle of the 12th century – there are records dating back to 1105 linking the Arnots to the area. In 1284 the lands are recorded as being in possession of Michael de Arnoth.
David Arnot of Fyfe rendered homage in 1296. The island of Ellenabot in Loch Lomond was confirmed to Matilda de Arnoth around 1320. He was was one of the 2,000 noble landowners who were required to swear allegiance to King Edward I of England.
Michael de Arnot, one of the garrison of Edinburgh Castle in 1337 may be the same Michael Arnoth mentioned in a letter of David de Manuel relating to the land of Kynglassy in 1340.
The knight Henricus de Arnot attested to the marches of Kyrknes and Louchor in 1395.
Arnot Tower was built in the early 1400s though there may have been earlier fortifications which occupied the site. The building seen today was probably built in 1507 at a time when a charter was granted making the lands a barony for the Arnot family of that ilk. There was a spiral staircase running from a vaulted cellar in the south-east corner (now collapsed) and there was a hall above and two upper storeys. The Arnots abandoned their tower around 1700 and it subsequently became a ruin. Nowadays, the castle and the adjoining gardens are used to host weddings and other functions.
As a ruin, Arnot Tower seems to have provided an inspiration for poets and painters. In 1760, Michael Bruce (1746 – 1767) wrote a poem about the love affair between two members of the Arnot and Balfour families (the latter based at Burleigh Castle ) who were in the middle of a bitter feud – bit like Romeo and Juliet.
Edward Arnott was repledged to the liberty of the burgh of Irvine in 1472 and in 1429 the lands of Arnot in the sheriffdom of Fyff were granted to John de Arnutis.
David Ernot was archdeacon of Lothian in 1502 and later became Bishop of Galloway.
The name relatively common in Edinburgh in the 15th and 16th centuries and George Arnot was a merchant burgess there in 1627.
Hugo Arnot published a History of Edinburgh in 1816.