Helen Violet Bonham Carter, Baroness Asquith of Yarnbury,, known until her marriage as Violet Asquith, was a British politician and diarist. She was the daughter of H. H. Asquith, Prime Minister from 1908 to 1916, and she was known as Lady Violet, as a courtesy title, from her father's elevation to the peerage as Earl of Oxford and Asquith in 1925. Later she became active in Liberal politics herself, and was a leading opponent of appeasement. She stood for Parliament and became a life peer.

Earl of Oxford and Asquith is a title in the Peerage of the United Kingdom. It was created in 1925 for the Liberal politician H. H. Asquith. He was Home Secretary from 1892 to 1895, Chancellor of the Exchequer from 1905 to 1908, Leader of the Liberal Party from 1908 to 1926 and Prime Minister of the United Kingdom from 1908 to 1916. Asquith was made Viscount Asquith, of Morley in the West Riding of the County of York, at the same time, also in the Peerage of the United Kingdom. This title is used as a courtesy title by the heir apparent to the earldom.