Mary Waldegrave, Countess Waldegrave, DBE (n̩e Mary Dorothea Palmer; 25 March 1850 Р8 November 1933) was a British peeress.
She was the daughter of Roundell Palmer (later Earl of Selborne) and his wife, Laura, a daughter of the 8th Earl Waldegrave. She was known to family and friends as "May".
On 5 August 1874, she married her first cousin, William Waldegrave, 9th Earl Waldegrave. Lord and Lady Waldegrave had three children:
In the 1918 Birthday Honours, Mary Waldegrave, Countess Waldegrave, was appointed a DBE for her work as Deputy President of the Somerset branch of the British Red Cross Society during World War I.