Sir Robert Grierson, 1st Baronet

Sir Robert Grierson of Lag
1st Baronet, of Lag and Rockhall
Cruel Lag's memorial at the Old Kirk of Dunscore burial ground, erected in 1897 by his descendant Sir Alexander Grierson.
Other namesCruel Lag, Auld Lag
Born1657
Barquhar, Lochrutton parish, Kirkcudbrightshire
Died29 December 1733(1733-12-29) (aged 75–76)
Dumfries
BuriedDunscore Old Kirk
NationalityScottish
Spouse(s)Lady Henrietta Douglas
ParentsWilliam Grierson, Margaret Douglas
OccupationJustice of the Peace, Member of Parliament

Sir Robert Grierson, 1st Baronet of Lag (1655 – 31 December 1733) was a Scottish baronet from Dumfriesshire.

He is best remembered as a notorious persecutor of the Covenanters, particularly among the people of Galloway, and is still referred to by nickname, "Cruel Lag".

The character of Sir Robert Redgauntlet of "Wandering Willie's Tale" in Sir Walter Scott's Redgauntlet is based on Grierson.