Born in Golden Square in Middlesex, he was the only son of Sir Wyndham Knatchbull-Wyndham, 5th Baronet and his wife Catharine, daughter of James Harris.
[2] In 1749, aged only twelve, Knatchbull-Wyndham succeeded his father as baronet.
[3] He was educated at Wadham College, Oxford until 1757 and began then his Grand Tour.
[4] After his return in 1760, he entered the British House of Commons, sitting as a Member of Parliament (MP) for Kent in the following three years.
[4] Knatchbull-Wyndham died, aged 26, unmarried and was succeeded in the baronetcy by his uncle Edward Knatchbull.