Sir Thomas Charles Bunbury, 6th Baronet (May 1740 – 31 March 1821) was a British politician and the first husband of Lady Sarah Lennox.
Bunbury was the eldest son of Reverend Sir William Bunbury, 5th Baronet, Vicar of Mildenhall, Suffolk, and his wife Eleanor, daughter of Vere Graham. The caricaturist Henry Bunbury was his younger brother. He was educated at St Catharine's College, Cambridge. Bunbury was returned to Parliament as one of two representatives for Suffolk in 1761, a seat he held until 1784 and again from 1790 to 1812. He was also High Sheriff of Suffolk in 1788.
Bunbury married firstly Lady Sarah, daughter of Charles Lennox, 2nd Duke of Richmond (a grandson of Charles II), and one of the famous Lennox sisters, in 1762. Their notorious marriage, which produced no children (although Sarah gave birth to a daughter by her lover Lord William Gordon in 1769), was dissolved by Act of Parliament in 1776 (on the grounds of Sarah's adultery). He married secondly a woman by the name of Margaret sometime after 1776. There were no children from this marriage either. Bunbury died in March 1821, aged 80, and was succeeded by his nephew, Henry. Margaret, Lady Bunbury, died in February 1822.
Bunbury was an important figure in the field of horse-racing. His influence has been described as "crucial". He was a steward of the Jockey Club and his horses included The Derby winners Diomed, Eleanor and Smolensko. His racing silks were pink and white stripes.