John Locke (pronounced /lɒk/; 29 August 1632 – 28 October 1704) was an English philosopher. Locke is considered the first of the British empiricists, but is equally important to social contract theory. His ideas had enormous influence on the development of epistemology and political philosophy, and he is widely regarded as one of the most influential Enlightenment thinkers, classical republicans, and contributors to liberal theory. His writings influenced Voltaire and Rousseau, many Scottish Enlightenment thinkers, as well as the American revolutionaries. This influence is reflected in the American Declaration of Independence.

Locke's theory of mind is often cited as the origin for modern conceptions of identity and "the self", figuring prominently in the later works of philosophers such as David Hume, Jean-Jacques Rousseau and Immanuel Kant. Locke was the first philosopher to define the self through a continuity of "consciousness". He also postulated that the mind was a "blank slate" or "tabula rasa"; that is, contrary to Cartesian or Christian philosophy, Locke maintained that people are born without innate ideas, and that knowledge is instead determined only by experience derived by sense perception.

Locke's father, who was also named John Locke, was a country lawyer and clerk to the Justices of the Peace in Chew Magna, who had served as a captain of cavalry for the Parliamentarian forces during the early part of the English Civil War. His mother, Agnes Keene, was a tanner's daughter and reputed to be very beautiful. Both parents were Puritans. Locke was born on 29 August 1632, in a small thatched cottage by the church in Wrington, Somerset, about twelve miles from Bristol. He was baptized the same day. Soon after Locke's birth, the family moved to the market town of Pensford, about seven miles south of Bristol, where Locke grew up in a rural Tudor house in Belluton.