Sir William Peryam (1534 – 9 October 1604) of Little Fulford, near Crediton in Devon, was an English judge who, in 1593, rose to the position of Lord Chief Baron of the Exchequer and was knighted by Queen Elizabeth I.
Peryam was born in Exeter, the eldest son of John Peryam, twice mayor of Exeter, and his wife Elizabeth, a daughter and co-heir of Robert Hone of Ottery. The year of Peryam's birth is known to history but, as was common in the 16th century, the day and month went unrecorded. Through his mother's sister, Joan Bodley née Hone, Peryam was cousin to Sir Thomas Bodley. Like the Bodleys, the Peryams were early adherents of Protestantism and were also threatened in the time of Marian persecutions. Under Queen Elizabeth however, the family thrived, with William eventually achieving eminence in law and his younger brother John Peryam (1541 – c. 1618), MP, elected to Parliament four times (Barnstaple 1584, Bossiney 1586, Exeter 1589 and 1593) and becoming Mayor of Exeter. The lawyer and politician William Hakewill and the clergyman and author George Hakewill were his nephews.
Young William was first educated in Exeter and then at Exeter College, Oxford where on 25 April 1551 he was elected fellow. He resigned his fellowship some months later and went to London where he eventually studied law at the Middle Temple, being called to the bar in 1565.
A slight setback in his career occurred in 1568 when, after having been summoned to Ireland by Sir Peter Carew to help him prosecute an ultimately successful claim to an Irish barony, Peryam received an unexpected appointment as judge under the prospective President of Munster, Sir John Pollard. By writing to Sir William Cecil and earnestly petitioning the Privy Council, mentioning his wife and children and delicate state of health, Peryam seems to have been able to avoid the transfer to Ireland altogether. Thereafter, his rise through the legal ranks was steady: in 1575 he became serjeant-at-law for the Michaelmas term, and on 13 February 1581, a Judge of the Court of Common Pleas. His highest office came in January 1593, when he was knighted and promoted to Lord Chief Baron of the Exchequer. Of his knighthood Prince wrote as follows: "Queen Elizabeth of blessed memory, as a signal testimony of her favour and his worth, was pleased to confer upon him the honour of knighthood, but not before he had been twelve years a judge, so cautious was that wise princess in conferring titles, lest they should become cheap and contemptible".