Wilmot, Sir John Eardley (1709–1792), judge, was born in Derby on 16 August 1709, the second son of Robert Wilmot (1669/70–1738), of Osmaston, Derbyshire, and his wife, Ursula, daughter and coheir of Sir Samuel Marow, bt, of Berkswell, Warwickshire. Robert was educated at Magdalen Hall, Oxford, and studied law at the Inner Temple; his grandfather Sir Nicholas Wilmot (1611–1682) was a prominent serjeant-at-law who was knighted at Hampton Court in 1674. Robert's two sons, Robert (c.1708–1772) and John Eardley, were also trained in law at the Inner Temple. The younger Robert, however, pursued a career in government service; he was knighted on 30 May 1739 and created a baronet on 10 October 1772.

John Eardley Wilmot attended the free school at Derby, after which he studied under the Revd Dr John Hunter at Lichfield, along with his contemporary Samuel Johnson and David Garrick, six years his junior. Wilmot later described his schoolmate Johnson as ‘a long, lank, lounging boy, whom he distinctly remembered to have been punished by Hunter for idleness’ (Wilmot, Memoirs, 6). Fortunately Hunter's thrashings, sometimes gratuitous, were compatible in both Johnson and Wilmot with instilling a love of learning and skill in Latin. Wilmot moved to Westminster School in January 1724, where the future first earl of Mansfield, William Murray, had entered five years earlier, and where Wilmot formed friendships that would last his lifetime. At Westminster School, and subsequently at Trinity Hall, Cambridge, where he was admitted as a fellow-commoner on 13 February 1727, Wilmot developed a passion for study, and was often heard to wish for an academic life as a Trinity fellow. He hoped to do this in the church, but yielded to his father's preference for the law, which he pursued with energy and discipline at the Inner Temple. He was called to the bar in 1732.

Little is known of Wilmot's early years at the bar, but John Hough, the bishop of Worcester, who was a close friend of the family, wrote to one of Wilmot's aunts on 4 May 1737:

I hear every body speak of your nephew Wilmot, as one of the most hopeful young gentlemen at the Bar … he may, without presumption aspire to any thing in the course of his profession; and has no small encouragement from what he has seen, since his acquaintance with Westminster-hall, in four or five of the long Robe, who have reached the top in the prime of their years. (Wilmot, Hough, 323)

Wilmot's son and biographer identified three of the ‘four or five of the long Robe’ as Charles Talbot, first Baron Talbot of Hensol; Philip Yorke, first earl of Hardwicke; and Sir Dudley Ryder, who was made attorney-general in 1736.

Throughout his life Wilmot expressed a longing for the quiet of country life. As he once wrote to a friend, ‘withdrawing from the eyes of mankind, has always been my favourite wish’ (Wilmot, Memoirs, 14). According to Campbell, ‘for many years he was able to remain unmolested’, but by going the midland circuit, and at the Derby assizes, ‘he was at last betrayed to Westminster Hall as a deep lawyer and powerful advocate’ (Campbell, 2.281). Attorney-General Ryder appointed Wilmot junior counsel to the Treasury, and in 1753, at Ryder's suggestion, Lord Chancellor Hardwicke proposed that Wilmot take silk and that he afterwards be made king's serjeant. Wilmot shrank from the honours, withdrawing wholly to Derbyshire with his family, which then consisted of his wife, Sarah (1721–1772), daughter of Thomas Rivett of Derby, whom Wilmot had married on 3 April 1743, and five small children.

Early in 1755, however, Sir Martin Wright resigned his post as a puisne king's bench judge, and Wilmot was nominated as Wright's replacement. He was knighted, called as a serjeant-at-law, and placed on the bench in February 1755. Following Hardwicke's resignation in August 1756, Wilmot became one of the commissioners of the great seal administering the duties of the lord chancellor, alongside Sir John Willes, chief justice of common pleas, and Sir Sidney Stafford Smythe, a baron of the exchequer. Wilmot had studied civil law avidly when at Cambridge, and, despite having had no equity practice, ‘seemed to have by intuition a wonderfully correct notion of it’ (Campbell, 2.286). He was among those who were proposed as Hardwicke's successor, but he would not hear of it, and on Sir Robert Henley's acceptance of the great seal in June 1757 Wilmot resettled into king's bench, where he served for almost ten years. There, he had an especially cordial and respectful working relationship with both Mansfield, the lord chief justice, and Sir Michael Foster, an expert on crown law. Mansfield in his early years on the court sent drafts of opinions to Wilmot, urging him to ‘put in, & put out, without Scruple’ (Oldham, 1.53–4). Another close friend was William Blackstone. After Blackstone had completed the first volume of his Commentaries he wrote to Wilmot on 22 February 1766:

Sir, Lord Mansfield did me the honour to inform me, that both you and himself had been so obliging as to mark out a few of the many errors, which I am sensible are to be met with in the Book which I lately published. Nothing can flatter me so much as that you have thought it worth the pains of such a revisal. (Wilmot, Memoirs, 201)

Despite the admiration for his abilities in London and at Westminster Hall, Wilmot continued to yearn for the country. Twice he sought, unsuccessfully, to transfer to the chief justiceship of Chester. His ascendancy in London, however, was yet incomplete. On the elevation to lord chancellor of Charles Pratt, Baron Camden, in August 1766, the chief justiceship of common pleas was offered to Wilmot. Against his inclination and on the importuning of his brother judge and good friend Sir Joseph Yates (whose winning argument was that life even as chief at common pleas would be peaceful compared to the burden carried by all of the king's bench judges) Wilmot relented and was sworn into his new post on 20 August 1766 on his return from the western circuit. Soon thereafter, on 10 September, he was sworn of the privy council.

By the end of the decade Wilmot's unremitting longing for a quieter life overpowered him. Not only did he decline the lord chancellorship yet again, on Camden's resignation in 1770, but by year's end he had determined to resign from common pleas. He resigned on 26 January 1771 but remained a privy councillor until 1782. He died at his house in Great Ormond Street, London, on 5 February 1792. During retirement he was supported by a pension of £2400, which he had fruitlessly resisted. He was buried in Berkswell church, Warwickshire. He and his wife had three sons and two daughters. The eldest son, Robert, died in Bengal; the second son, John, author of his father's memoirs, practised as a barrister, became a master in chancery, and succeeded to the estate.

Wilmot discharged his responsibilities on the bench with integrity and ability. In matters affecting the crown and the government he customarily took what he considered to be the moral high ground and was no friend to freedom of the press. He was on king's bench during the prosecutions of John Wilkes and in other seditious libel cases. An illustration appears as an appendix to his son's Memoirs of Sir John Eardley Wilmot, reprinting the sentence Wilmot pronounced against John Williams, convicted for publishing number forty-five of Wilkes's North Briton. Wilmot stated:

To such a pitch is the licentiousness of this age grown, that scarce a day passes without a malevolent endeavour to defame some measure of Government, some decision of a Court of Justice, or some public or private character … Liberty can exist only under an empire of laws, made with the concurrence of the people; and therefore cannot be more dangerously wounded than by the resistance encouraged and applauded in this Paper. (Wilmot, Memoirs, 228–9)

Besides Wilkes, another campaigner for freedom of the press was John Almon, who in 1764 published A letter concerning libels, warrants, the seizure of papers, and sureties for the peace or behaviour. For this he was prosecuted by attachment for contempt of court, a form of action that could be initiated directly by the law officers of the crown without the interposition of a grand jury. The case was heard by king's bench, sans Mansfield, and Wilmot prepared a lengthy opinion upholding the attachment, but the prosecution was withdrawn before the opinion was issued. Wilmot's son John published it nevertheless in 1802 in Notes of Opinions and Judgments Delivered in Different Courts. The opinion is balanced and elegant; it exemplifies why Wilmot was so highly respected by his peers. Urging deference to the wisdom of many ages, Wilmot wrote:

The Trial by Jury is one part of [the nation's legal] System; the punishing Contempts of the Court by Attachment is another; we must not confound the modes of Proceeding … We must give that energy to each, which the Constitution provides … I am sure it wants no great intuition to see, that Trial by Juries will be buried in the same grave with the Authority of the Courts who are to preside over them. (Wilmot, Notes of Opinions, 259)

James Oldham