Roxburgh Castle is a ruined royal castle that overlooks the junction of the rivers Tweed and Teviot, in the Borders region of Scotland. The town and castle developed into the royal burgh of Roxburgh, which the Scots destroyed along with the castle after capturing it in 1460. Today the ruins stand in the grounds of Floors Castle, the seat of the Duke of Roxburghe, across the river from Kelso.

Roxburgh is a civil parish and formerly a royal burgh, in the historic county of Roxburghshire in the Scottish Borders, Scotland. It was an important trading burgh in High Medieval to early modern Scotland. In the Middle Ages it had at least as much importance as Edinburgh, Stirling, Perth, or Berwick-upon-Tweed, for a time acting as de facto capital.