Henry Frederick Thynne, 6th Marquess of Bath JP (26 January 1905 – 30 June 1992), styled Lord Henry Thynne until 1916 and Viscount Weymouth between 1916 and 1946, was a British aristocrat, landowner and Conservative Party politician.
Lord Bath was the second but eldest surviving the son of Thomas Thynne, 5th Marquess of Bath and Violet Mordaunt, the illegitimate daughter of Harriet Mordaunt and Lowry Cole, 4th Earl of Enniskillen. He was educated at The New Beacon Preparatory School, Harrow and Christ Church, Oxford. In 1916 he became the heir to the family titles and estates after his elder brother John was killed in action in the First World War.
In the 1920s the tabloid press considered him one of the bright young things.
As Viscount Weymouth, he was elected as the Member of Parliament (MP) for Frome between 1931 and 1935, and served as a member of the Council of the Duchy of Cornwall from 1933 to 1936 and Justice of the Peace for Wiltshire in 1938.
He gained the rank of Major in the service of the Royal Wiltshire Yeomanry, fought in the Second World War, and was awarded the Bronze Star and the Silver Star for actions during that period.