Una Mary Ross, 25th Baroness de Ros of Helmsley was a British peer. She succeeded her mother to the title in 1943. She was the daughter of Anthony, 3rd Earl of Dartrey, and his wife, Mary, Countess of Dartrey, who held the barony in her own right.
- Occupation
- politician
- Citizenship
- United Kingdom, United Kingdom of Great Britain and Ireland
- Born
- October 5, 1879
- Died
- October 9, 1956
