| Honorific-Prefix: | The Most Honourable |
| The Marquess of Bath | |
| Honorific-Suffix: | KG |
| Office: | Lord Lieutenant of Somerset |
| Term Start: | 1819 |
| Term End: | 1837 |
| Predecessor: | The Earl Poulett |
| Successor: | The Earl of Ilchester |
| Birth Date: | 25 January 1765 |
| Death Date: | 27 March 1837 (aged 72) |
| Alma Mater: | St John's College, Cambridge |
| Children: | 11, including: |
Thomas Thynne, 2nd Marquess of Bath KG (25 January 1765 – 27 March 1837), styled Viscount Weymouth from 1789 until 1796, was a British peer.
Thynne was the eldest son of Thomas Thynne, 1st Marquess of Bath, and Lady Elizabeth Cavendish-Bentinck. He succeeded as 2nd Marquess in 1796 on the death of his father.
He was educated at Winchester College and admitted as a nobleman to St John's College, Cambridge in 1785, graduating M.A. in 1787.
Between 1786 and 1790, he was MP (Tory) for Weobley. He later sat for Bath from 1790 to 1796. He was Lord Lieutenant of Somerset between 1819 and 1837 and was invested as a Knight of the Garter on 16 July 1823.
He was a benefactor in the nearby town of Frome, giving up land and buildings so that a new wide road could be created leading south from the town centre, now called Bath Street. On another occasion he set aside land for allotments for a hundred families. "I have been told that at a certain hour in the morning he would admit the humblest persons in his parish, listen to their little concerns, and advise them.....He was one of the few who well understood for what purposes rank, wealth, and influence, are conferred."[1]
Lord Bath died in 1837, aged 72, and was buried at his home, Longleat House. "I was told ten thousand were present, one hundred and fifty horsemen."[2] His eldest son Thomas predeceased him by some two months and he was therefore succeeded by his second son Henry.
Lord Bath married the Honourable Isabella Elizabeth Byng (21 September 1773 – 1 May 1830), daughter of George Byng, 4th Viscount Torrington, on 14 April 1794. They had eleven children: