The ruins of Cessford Castle lie near the village of Cessford, which lies several miles south of Kelso in the Scottish Border, and was a stronghold for Clan Kerr. The lands had originally been held by the Sinclairs, but passed to the Kerrs. The Cessford Kerrs soon afterwards became rivals with the nearby branch of Kerrs in Ferniehirst
The now three storey L-plan castle dates from around 1450, and was built by Andrew Ker, ancestor of Robert Ker, 1st Earl of Roxburghe, and the future Dukes of Roxburghe. It is from these lands that the Duke takes his subsidiary titles: Baron Ker of Cessford, and Marquess of Bowmont and Cessford.
It is thought that the castle may have incorporated an earlier structure when it was built. In its prime, Cessford Castle was considered a formidable fortress which was up to six storeys tall with some walls up to 4 metres thick. To further protect the castle there was a curtain wall that surrounded it, apparently followed by another wall and a ditch further on. Throughout the middle of the 16th century, Cessford Castle was a frequent target of the English who deemed the stronghold one of the strongest fortress in all of Scotland. In 1519 it was damaged by the English, and then four years later, in 1523, they was besieged the castle. The English attacked Cessford again in 1543, torching the castle, and then going on to sack the place the following year.
Sir Walter Kerr of Cessford was also a Warden of the Marches, but after his involvement in the murder of Walter Scott of Buccleuch in 1552, and for being an active opposer of Mary, Queen of Scots, he was banished to France. This branch of Kerrs fought against the Queen at the Battle of Langside in 1568.
The castle was eventually abandoned in 1650 when the last occupiers left, and stone and materials were taken later for the construction of Floors Castle.