Eton College (/ˈiːtən/ ^ⓘ EE-tən) is a public school providing boarding education for boys aged 13–18, in the small town of Eton in Berkshire. The school is the largest boarding school in England, ahead of Millfield and Oundle.

Eton charges up to £52,749 per year (£17,583 per term, with three terms per academic year, for 2023/24). It was the sixth most expensive Headmasters' and Headmistresses' Conference boarding school in the UK in 2013–14.

It was founded in 1440 by Henry VI as Kynge's College of Our Ladye of Eton besyde Windesore, making it the 18th-oldest school in the Headmasters' and Headmistresses' Conference (HMC). Originally intended as a sister institution to King's College, Cambridge, Eton is known for its history, wealth, and notable alumni, known as Old Etonians. It has educated prime ministers, world leaders, Nobel laureates, Academy Award and BAFTA award-winning actors, and generations of the aristocracy, and has been referred to as "the nurse of England's statesmen".

Eton is one of four public schools, along with Harrow (1572), Radley (1847) and Sherborne, to have retained the boys-only, boarding-only tradition, which means that its boys live at the school seven days a week during term time. The remainder of them, including Charterhouse in 1971, Westminster in 1973, Rugby in 1976, Shrewsbury in 2015, and Winchester in 2022, have since become co-educational.

Eton College was founded by Henry VI as a charity school to provide free education to 70 poor boys who would then go on to King's College, Cambridge, founded by the same king in 1441. Henry used Winchester College as a model, visiting at least six times (in 1441, 1444, 1446, 1447, 1448, 1449, 1451, 1452) and having its statutes transcribed. Henry appointed Winchester's headmaster, William Waynflete, as Eton's Provost, and transferred some of Winchester's 70 scholars to start his new school.

When Henry VI founded the school, he granted it a large number of endowments, including much valuable land. The group of feoffees appointed by the king to receive forfeited lands of the Alien Priories for the endowment of Eton were as follows:

It was intended to have formidable buildings; Henry intended the nave of the College Chapel to be the longest in Europe, and several religious relics, supposedly including a part of the True Cross and the Crown of Thorns. He persuaded the then Pope, Eugene IV, to grant him a privilege unparalleled anywhere in England: the right to grant indulgences to penitents on the Feast of the Assumption. The college also came into possession of one of England's Apocalypse manuscripts.

However, when Henry was deposed by King Edward IV in 1461, the new King annulled all grants to the school and removed most of its assets and treasures to St George's Chapel, Windsor, on the other side of the River Thames. Legend has it that Edward's mistress, Jane Shore, intervened on the school's behalf. She was able to save a good part of the school, although the royal bequest and the number of staff were much reduced. Construction of the chapel, originally intended to be slightly over twice as long, with 18, or possibly 17, bays (there are eight today) was stopped when Henry VI was deposed. Only the Quire of the intended building was completed. Eton's first Head Master, William Waynflete, founder of Magdalen College, Oxford and previously headmaster of Winchester College, built the ante-chapel that completed the chapel. The important wall paintings in the chapel and the brick north range of the present School Yard also date from the 1480s; the lower storeys of the cloister, including College Hall, were built between 1441 and 1460.