Tweeddale, Ettrick and Lauderdale was a constituency of the Scottish Parliament (Holyrood).

The other eight constituencies of the South of Scotland region were: Ayr, Carrick, Cumnock and Doon Valley, Clydesdale, Cunninghame South, Dumfries, East Lothian, Galloway and Upper Nithsdale and Roxburgh and Berwickshire.

The rest of the Scottish Borders area were covered by the Roxburgh and Berwickshire constituency.

Following their First Periodic review into constituencies for the Scottish Parliament, the Boundary Commission for Scotland recommendated altering the Tweedale, Ettrick, and Lauderdale constituency into a newly formed Midlothian South, Tweedale and Lauderdale seat.

The neighbouring constituency is an altered Ettrick, Roxburgh and Berwickshire seat.