| Pre-Nominals: | The Right Honourable |
| The Lady Alington | |
| Birth Date: | 3 October 1902 |
| Birth Place: | London, England |
| Death Place: | London, England |
| Burial Place: | Witchampton, East Dorset, England |
| Children: | Mary Anna Marten |
| Occupation: | Socialite |
Mary Sibell Sturt, Baroness Alington (born Lady Mary Sibell Ashley-Cooper; 3 October 1902 – 2 August 1936) was an English socialite and member of the Bright Young Things.[1] [2]
Lady Mary Ashley-Cooper was born in 1902 in London,[3] the eldest daughter of Anthony Ashley-Cooper, 9th Earl of Shaftesbury and Lady Constance Sibell Grosvenor.[4] Queen Mary was her godmother.[1]
On 27 November 1928, Lady Mary Sibell Ashley-Cooper married Napier Sturt, 3rd Baron Alington (1896–1940) at St Margaret's, Westminster.[1] They had one daughter, Hon. Mary Anna Sibell Elizabeth Sturt (1929–2010).
Tall and athletic, Lady Alington was a champion swimmer. She was a member of the Bath Club and in 1934 won the club's swimming title.[1]
In 1936, she died after an operation for acute appendicitis, aged 33 years old.[1] She is buried at All Saints Churchyard, Witchampton. Her husband died of pneumonia while on active service during World War II in Cairo and is buried there.