Thomas Dundas, 2nd Earl of Zetland, KG KT (5 February 1795 – 6 May 1873), was a distinguished British nobleman and politician.

Born in Marylebone, London, he received his education at Harrow School and Trinity College, Cambridge. In 1818, he was elected as the Whig Member of Parliament for Richmond, a seat previously held by his father and grandfather, and later became the representative for York. He re-joined Parliament in 1835 as the member for Richmond and succeeded his father as the second Earl of Zetland in 1839.

A prominent freemason like his father, Lord Zetland served as the Grand Master of the United Grand Lodge of England from 1844 to 1870. He was also a senior member of the Jockey Club and celebrated the victory of his horse, Voltigeur, in the Epsom Derby and St Leger Stakes in 1850.

Upon his succession to the earldom, he was named Lord Lieutenant and Custos Rotulorum of the North Riding of Yorkshire, and in 1861, he was honoured as a Knight of the Thistle. He relinquished the Order upon his appointment as a Knight of the Garter in 1872 and passed away the following year at Aske Hall, Yorkshire.