Sir Wyndham Knatchbull-Wyndham (1737-1763), 6th Baronet, was the only son of Sir Wyndham Knatchbull-Wyndham, 5th Baronet and his wife Catharine, daughter of James Harris. He succeeded his father as baronet at the age of twelve. He became MP for Kent in 1760; at the time of the election he was still on his Grand Tour, but was proposed as a candidate by the Kent Whigs, led by Sir George Oxenden. Sir Edward Dering withdrew and Knatchbull Wyndham was returned unopposed. At the general election of 1761 he stood jointly with Robert Fairfax and was again returned without a contest. He died unmarried at the age of twenty-six.