Thomas Dundas, 2nd Earl of Zetland, KG (February 5, 1795) - (May 6, 1873) was a British politician and nobleman. Born in Marylebone, London, he was educated at Harrow and Trinity College, Cambridge. In 1818 he was elected Whig Member of Parliament for his father and grandfather's old seat of Richmond, becoming representative for York twelve years later. In 1835 he returned to Parliament as member for Richmond, and four years later succeeded his father as second Earl of Zetland.

Like his father a prominent freemason, Lord Zetland was the English Society of Freemason's grandmaster from 1844 to 1870. In the year of his succession to the earldom he was appointed Lord Lieutenant of the North Riding of Yorkshire, and in 1861 became a Knight of the Thistle. He resigned the Order on being made a Knight of the Garter in 1872, and died the following year at Aske Hall, Yorkshire.