Margaret Gillies (7 August 1803– 20 July 1887) was a London born Scottish watercolourist. Adopted aged three by her uncle Lord Gillies, a judges who introduced her to Edinburgh literary society, and her cousin, the portraitist Colvin Smith.
In 1819 she returned to London, becoming a pupil of the miniaturist Frederick Cruikshank. She exhibited large miniatures, chiefly in watercolour and gum on ivory, at the R.A. 1832-61, the Society of British Artists 1834-42, the Royal Scottish Academy 1834-52, and the Liverpool Academy 1839-49.
Many of her sitters were important writers, intellectuals, and social reformers. From the 1840's she specialised increasingly in larger subject pictures, widely exhibited. Elected a member of the O.W.S. in 1852. After 1851 her work became increasingly religious in tone and allegorical in subject. She travelled widely, across the UK, France and Italy, and exhibited at least 461 works during her lifetime.