Sir Thomas married Catherine, (daughter of Edward Stanley, 3° E. Derby), March 4, 1565, by settlement.

National Archives (UK)
Reference: KNY 13 369 x 2
Covenant bond from Thomas Knyvett Esq. of Buckenham Castle to John Flowerdewe gent. of Hethersett, (1552).

Reference: KNY 14 369 x 2
Acknowledgment of receipt
From Sir Thomas Knyvett of Buckenham to John Flowerdew gent. of £120 part purchase money for moiety of the manor of Hethersett, (1560).

Reference: KNY 436 371 x 9
Bond
From Edward Flowerdewe gent. of Hethersett to Thomas Knyvett Esq. of Ashwellthorpe to idemnify him as surety for bond debt of 200 marks of said Edward to Elizabeth Foster gent. [sic] of Wymondham, (1564).

Reference: Phi/551 578 x 2
Exemplification of account in the Court of Wards of Roger Woodhouse Esq. one of the executors of Sir Thomas Knyvett knight late of Buckenham Castle, Mich. 1571-Mich. 1573, (March 2, 1580).