Hermitage Castle is a castle in the border region of Scotland. It is under the care of Historic Scotland.

It is thought that the name derives from Old French: l'armitage - guardhouse. It was known as the 'the guardhouse of the bloodiest valley in Britain' , another name for Liddesdale.

Supposedly built by one Nicholas de Soulis around 1240, in a typical Norman Motte and Bailey pattern. It stayed in his family until approximately 1320 when his descendant, William de Soulis was forfeited on account of witchcraft and the attempted regicide of King Robert I. In 1338 the latest incumbent of many, Englishman Sir Ralph de Neville was besieged by Sir William Douglas, The Knight of Liddesdale, known as the "Flower of Chivalry", although his behaviour seems far from gentlemanly. Upon his death, brought about by near kinsman and namesake, William Douglas, 1st Earl of Douglas it fell into the hands of the Dacre family for a time, it soon fell back into the hands of Earl William, through inheritance and it was he that enabled the construction of most of the present building, possibly with the help of master mason, John Lewin of Durham. The Earl's sons provided the seed of the two famous branches of the house - the 'Black' (for Earls of Douglas) and 'Red' (for the Earls of Angus). By 1455 the Black line had so incensed the King that James Douglas, 9th Earl of Douglas was forfeited never to return, and the benficences that they had enjoyed, passed to the 'Red' line of Angus, including Hermitage Castle.

In 1492, King James IV was suspicious of the then, Earl of Angus, Archibald, Bell the Cat and ordered him to yield The Hermitage to the Crown in return for other lands of less strategic value this was brought about by the rise to power of the Hepburns of Bothwell, and Angus yielded and took Bothwell Castle, Hepburn took Hermitage.

The castle passed to James Hepburn, 4th Earl of Bothwell, and Mary I of Scotland made a famous marathon journey on horseback to visit him there, only a few weeks after the birth of her son.