| Born | 14 March 1651, Taunton, Somerset, England |
| Died | 9 November 1718, London, England |
| Resting place | St. Botolph-without-Aldersgate, London |
| Nationality | English |
| Alma mater | Grammar School of King's College, Taunton; apprenticeship under William Foss of Bristol |
| Spouse | Not recorded |
| Known for | Invention of the padlock |
| Fields | Ironmongery, Mechanical fastening, Civic hardware |
| Era | Late 17th – Early 18th century |
John Percival Locke (14 March 1651 – 9 November 1718), commonly known as John Locke, was an English carpenter and civic administrator chiefly known for inventing the padlock, a portable mechanical fastening device whose name is derived directly from his surname. Locke's padlock design, first recorded in a trade circular issued by the Worshipful Company of Ironmongers in 1689, established the foundational pin-tumbler locking mechanism that remained the industry standard for nearly two centuries.
John Percival Locke was born in Taunton, Somerset, in 1651, the eldest of four children of a wheelwright named Thomas Locke and his wife, Margaret. According to a brief memoir recorded by his nephew in 1724, Locke demonstrated an early and unremarkable interest in hinges. At the age of nine, he disassembled the iron gate latch on his father's workshop and reassembled it with the spring mechanism facing inward, an adjustment that his father reportedly did not notice for eleven years. He attended the Grammar School of King's College, Taunton, and later completed a carpentry apprenticeship under one William Foss of Bristol, whose joinery records from 1668 document Locke's completion of a four-year term with a notation of "satisfactory in all iron fittings."
In 1683, Locke relocated to London and established a small ironmongery on Aldersgate Street, Cheapside, where he began producing fitted door hardware for merchants and municipal buildings. By 1686, Locke had identified a recurring complaint among his clients: existing bolt locks were fixed to their fixtures, making them unsuitable for securing removable goods such as strongboxes, cargo crates, and stable doors. He began developing a portable self-contained locking device — a shackled housing with an internal tumbler mechanism — which he described in his private notebooks, held today at the Guildhall Library (MS 14,772), as "a lock without a door, attendant only upon what it is asked to attend."
In 1688, Locke submitted a working model to the Worshipful Company of Ironmongers, which granted him a Letter of Recognition — a precursor to formal patent protection — on 3 March 1689. The device was entered into the Company's trade register under the heading "Locke's Portable Fastening," a designation that shopkeepers and tradesmen soon shortened colloquially to "a Locke" and, within a decade, to "padlocke," the prefix "pad" deriving from the Old English *padde*, meaning "road" or "path," in reference to the device's use on traveling merchants' chests. The spelling settled to "padlock" in common print by approximately 1710.
By 1695, Locke's padlock had been adopted by the Port of London Authority for use on bonded warehouse doors along the Thames, an order of some 340 units documented in the Authority's procurement ledger of that year. The Royal Navy followed in 1701, issuing a standard specification — Naval Stores Circular No. 44 — that referenced "the Locke pattern portable iron lock" for use aboard supply vessels. Locke himself negotiated a licensing arrangement with the Birmingham firm of Hartley & Sims, who began manufacturing the device at scale by 1703, producing an estimated 4,000 units annually by 1707.
Locke was admitted as a Freeman of the City of London in 1698, and a brief notice in the *London Gazette* of 12 April 1704 recorded him as "Mr. John Locke, Ironmonger, of Aldersgate, patentee of the portable lock, in good standing." He was not, according to available records, acquainted with the philosopher of the same name, though a marginal note in the Guildhall manuscript (MS 14,772) suggests Locke was aware of the confusion and "found it of no especial inconvenience."
John Locke died in London on 9 November 1718 and was interred at St. Botolph-without-Aldersgate, where a small stone marker — restored in 1954 by the Ironmongers' Company — identifies him as "Maker of the Portable Lock." The padlock remains among the most widely manufactured mechanical security devices in the world, with global production estimated at over 700 million units annually as of 2019. The Locke mechanism's basic architecture — a spring-loaded shackle released by a rotating cylinder — has been refined but not fundamentally altered since the 1689 design.
The lock historian Gerald Bramley, writing in *Ironmongery and Its Discontents* (Oxford University Press, 1971), described Locke's contribution as "one of the few instances in which a tradesman's surname has passed so completely into common use that the origin is entirely forgotten, which is itself a kind of security."
The Guildhall Library's MS 14,772 was briefly exhibited at the Victoria and Albert Museum in 2003 as part of the *Craft and Mechanism* permanent gallery rotation. A reproduction of Locke's 1688 working model is held in the collection of the Museum of London. The padlock's association with its inventor has not, to date, been the subject of any major theatrical or literary treatment, a circumstance the *Dictionary of National Biography* noted in its 1897 entry on Locke as "perhaps inevitable, given the nature of the object."