Selkirkshire or the County of Selkirk is a registration county of Scotland. It borders Peebles to the west, Midlothian to the north, Berwick to the north-east, Roxburgh to the east, and Dumfries to the south.

Selkirkshire was a constituency represented in the House of Commons of the Parliament of the United Kingdom from 1708 until 1868, when it was combined with Peeblesshire to form Peebles and Selkirk. The county town of Selkirk was represented separately as part of the Lanark Burghs constituency until 1832 when it was combined with Selkirkshire.