Thomas, (name also spelt Knevett), was christened February 22, 1624 at Ashwellthorpe, Norfolk, England. He was known as Knyvet of Mutford.

He married Emma Hayward, (also written as Amy Howard), daughter of Thomas Haward, on September 29, 1650 at St Mary's In The Marsh, Norwich, England. She was born about 1628 at Cranwise, Norfolk, England and died 1658. Her Will was dated April 1, 1658 and proved May 10, 1658.

Thomas died June 30, 1658 and was buried July 2, 1658 at Ashwellthorpe.

National Archives (UK)
Reference: KNY 509, 510 372 x 1
Grant by Thomas Knyvett Esq. to Anthony Knyvett Esq. of Westminster of life annuity of £10 from messuage and 180a. in Wreningham and grant of similar annuities after Anthony's death to Thomas's niece Mary Page and Anthony's cousin and niece Elizabeth Payne, (1649).

Reference: KNY 521 372 x 1
Settlement after the marriage of Thomas son of Thomas Knyvett sen. and Emme his wife re Blackhall in Wymondham and lands there and in Fundenhall and 10a. part of Fundenhall Wood, (1652)

Reference: KNY 611 372 x 5
Thomas Knyvett, Kenninghall Place, a brother
Urging him to court one of Sir Symonds D'Ewes' daughters, (1652).

Reference: Phi/556 578 x 3
Exemplification of pleading in Chancery between Thomas Leigh Esq. and Thomas Cary Esq. re Poyle Park, Surrey, in which Thomas Knyvett Esq. of Ashwellthorpe was concerned as heir of Thomas, Lord Knyvett of Escricke, (July, 1656).

British Libray of Manuscripts
Reference: Add. 34653 f. 123
Knyvett (Thomas). of Ashwelthorpe, co. Norf. Lease in Dunwich, (1648).