Ferniehirst Castle (sometimes spelled Ferniehurst) is an L-shaped construction on the east bank of the Jed Water, about a mile and a half south of Jedburgh, in the Scottish Borders area of Scotland, and in the former county of Roxburghshire.

In September 1523, an English force came to burn Jedburgh, and Lord Dacre was sent with 700 men and artillery to take the castle, which "stood marvellous strongly with a great wood".

The English were dislodged by a force of Sir John Ker's clansmen, and the Earl of Huntly reinforced by André de Montalembert and French auxiliaries led by Captain Pierre Longue in February 1549.

The French soldier Jean de Beaugué described the recapture and the fate of the English captain and garrison,[3] and the aristocrat and priest Alexander Gordon wrote an eyewitness account.

[5] When Mary, Queen of Scots, was exiled in England, her brother Regent Moray heard rumours in August 1568 that she would escape from Bolton Castle and be brought to Ferniehirst.

[9] James VI attacked the castle in 1593 as the Kers had assisted Francis Stewart, 5th Earl of Bothwell, who had conspired against the king.

The story is that in 1513 when the left-handed Sir Andrew Kerr came back from the Battle of Flodden, he had his men learn to use their left hands when swordfighting.