Sir Thomas Knyvet (died 1605), of Ashwellthorpe, Norfolk and Stradbroke, Suffolk, was an English politician.
He was the eldest son of Sir Thomas Knyvet of Ashwellthorpe, was educated at Queens' College, Cambridge (1584) and studied law at the Middle Temple (1591). He was knighted in 1603.
He was appointed Purveyor of the Tower Mint in 1600. He was elected a
Member (MP) of the Parliament of England for Aldeburgh in 1593 and
Thetford in 1601.
On his death he was buried at Feltwell, Norfolk. He had married Elizabeth, the daughter and coheiress of Nathaniel Bacon of Stiffkey, Norfolk, with whom he had 2 sons, one of whom was the Royalist JP Thomas Knyvett, and a daughter.
As Knyvet died in his father's lifetime, probably aged under 40, he never became prominent in the county. His parents, who seem to have had puritan sympathies, supported Nathaniel Bacon, later Thomas's father-in-law, and Thomas Farmer in their quarrel against Sir William Heydon and Sir Edward Clere, one of the more notorious disputes in a faction-ridden county. Knyvet himself possibly owed his return at Aldeburgh to his relatives the Woodhouses of Kimberley, and at Thetford to (Sir) John Fortescue, his mother's half-brother, who had been acting chancellor of the duchy of Lancaster earlier in 1601, and who was appointed chancellor soon after Parliament met. His elder son Thomas, who claimed the title Lord Berners, and married a daughter of Thomas Lord Burgh, succeeded to the family estates in 1617.