Lady Mary Ilona Margaret Whitley (née Cambridge; 24 September 1924 – 13 December 1999) was a relative of the British royal family.

Lady Mary was born at 19, Lowndes Square, Kensington, to the Earl and Countess of Eltham, later the Marquess and Marchioness of Cambridge.

Lady Mary's mother was born Dorothy Isabel Westenra Hastings, a granddaughter of the 14th Earl of Huntingdon.

Mary was a junior bridesmaid at the 1934 wedding of her father's first cousin, Prince George, Duke of Kent to Princess Marina of Greece and Denmark.

[4] She participated in the coronations of both King George VI[5] and Queen Elizabeth II and attended the Trooping the Colour every year between 1950 and 1999 (excluding 1955, when it was cancelled due to a rail strike).