Sir Thomas Fanshawe KB (1580 – 17 December 1631) was an English government official and politician who sat in the House of Commons between 1601 and 1629. Fanshawe was the second son of Thomas Fanshawe and first son by his second wife Joan Smythe, daughter of Customer Smythe and was baptised on 15 September 1580. His father was Queen's Remembrancer of the Exchequer. He was educated at Queens' College, Cambridge and admitted at the Inner Temple in 1595. He was an auditor for the Duchy of Lancaster. In 1601, he inherited the estate of Jenkins and Barking Manor, Essex, on the death of his father.