He was the son of Thomas Jermyn and Catherine Bernard. He served as
Sheriff of Norfolk and Suffolk in 1530 and 1541. On 10 March 1540, he was knighted by
Henry VIII and granted a coat-of-arms. Jermyn lived at
Rushbrooke Hall, which he demolished and remodelled in the late 1540s. He married first Anne Spring (1494–1528), daughter of
Thomas Spring of Lavenham, by whom he was the father of Sir
Ambrose Jermyn. He married secondly Anne Drury, widow of Sir George Waldegrave, esquire (c. 1483 – 8 July 1528) of
Smallbridge, Suffolk and daughter of Sir
Robert Drury (speaker). He left a lengthy will, proved 16 December 1552. ==References==