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 politician, aristocrat and landowner.
Lord Bath was second but eldest surviving the son of Thomas Thynne, 5th Marquess of Bath and Violet Mordaunt, and was educated at 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 group it called the Bright Young People.
As Viscount Weymouth, he was elected Conservative Member of Parliament 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..
Thynne succeeded his father as Marquess of Bath in 1946. He was noted for his forestry work on the ancestral estate of Longleat. It was he who developed the safari