Liddel Castle is a ruined castle in Liddesdale, by the Liddel Water, near Castleton in the Scottish Borders area of Scotland, in the former county of Roxburghshire. Liddel Castle is a scheduled monument.
A motte and bailey castle was built by Ranulf I de Soules in the 12th century after being granted the Lordship of Liddesdale by David I of Scotland. The castle was constructed on a bluff above the east bank of Liddel Water and protected on two sides by the Kirk Cleuch Burn. Liddel castle probably served as the caput of the barony.
- Coventry, Martin (2010). Castles of the Clans. Musselburgh: Goblinshead. ISBN 978-1-899874-36-1.
- Jeffrey, A. (1855-64) The history and antiquities of Roxburghshire and adjacent districts from the most remote period to the present time, 4v, London; Edinburgh, Page(s): Vol.4, 232, Held at RCAHMS D.1.3.JEF.R
- Historic Environment Scotland. "Liddel Castle (67934)". Canmore.
- RCAHMS record of Liddel Castle
- Scottish Borders Council: Heritage Sites Around Newcastleton[permanent dead link]
- Geograph image: Pasture near Liddel Castle