Mary Louisa Bruce, Countess of Elgin and Kincardine (née Lambton; 8 May 1819[2] – 9 March 1898) was a British aristocrat and writer.

She was the daughter of John Lambton, 1st Earl of Durham and his second wife Louisa Elizabeth Lambton (née Grey), daughter of Charles Grey, 2nd Earl Grey.

She later returned to Canada with her husband, James Bruce, 8th Earl of Elgin, from 1847 to 1853.

An accomplished artist, she studied under John Richard Coke-Smyth, alongside her sister, Lady Emily Augusta, and travel companion, Katherine Ellice.

She wrote and illustrated journals and diaries of her international travels.