Roxburghshire or the County of Roxburgh (Siorrachd Rosbroig in Gaelic) is a registration county of Scotland. It borders Dumfries to the west, Selkirk to the north-west, and Berwick to the north. To the south-east it borders Cumbria and Northumberland in England.

Roxburghshire was a constituency represented in the House of Commons of the Parliament of the United Kingdom from 1708 until 1918, when it was combined with Selkirk (from Peebles and Selkirk to from Roxburgh and Selkirk. The constituency was again adjusted in 1955 with the addition of Peebles to form Roxburgh, Selkirk and Peebles and again in 1983 to Roxburgh and Berwickshire. The latest incarnation is Berwickshire, Roxburgh and Selkirk formed in 2005.