Kilkenny College is a Church of Ireland co-educational day and boarding secondary school located in Kilkenny, in the South-East of Ireland. It is the largest co-educational boarding school in Ireland. In 2013 it transferred to the state/public sector and no longer charges fees for schooling. The school's students are mainly Protestant (Church of Ireland), although it is open to other denominations.

The college motto Comme je trouve, which means "As I find" in French, comes from the family coat of arms of the Butlers, an aristocratic family in the area and former patrons of the school. It is intended to encourage grit, striving through adversity and taking life's challenges head on.

It was founded in 1538 to replace the School of the Vicars Choral, which had been founded in 1234. Piers Butler the Earl of Ormond located it in the city centre. It was moved to its current location on the outskirts of Kilkenny in 1985.

Founded in 1538 by Piers Butler, 8th Earl of Ormond and his wife, Margaret, Kilkenny Grammar School as was then called was located to the west of the cathedral and sited beside the library of St Canice's Cathedral. The 1538 school replaced the older School of the Vicars Choral, which was founded in 1234. It was closed for a period in the 1650s (because of the English civil war that spilled over into Ireland), reopening as Kilkenny College in 1667 under the auspices of James Butler, 1st Duke of Ormond, following the Butler tradition of promoting education in the city. It soon became a famous school and so, in the 1780s, a new college was built on the same site overlooking the river Nore on John Street.

In 1985 the college was relocated to the 63-acre (250,000 m²) site at Celbridge House on the outskirts of the city, while the old school with its Georgian buildings and elegant facade, now known as County Hall, houses the offices of Kilkenny County Council within Kilkenny city centre.

At one time the college was termed a university and boasted a complement of three professors. In contrast, the end of the 19th century saw the college reduced to one pupil. The amalgamation with the nearby Pococke school was its saving. Twenty-nine headmasters of Kilkenny College are recorded, including such notable figures as Edward Jones, Bishop of St Asaph and John Mason Harden. In the 20th century there were four long-serving men: C.G. Shankey 1917 - 1952; Gilbert Colton 1953–1979; Samuel McClure 1979–1996; Canon Robert John Black 1996–2005. E. R. Dodds, the famous classicist and Michael Cusack also taught at the school.

During Gilbert Colton's time the school was amalgamated with the Collegiate School Celbridge in 1973 and Kilkenny College became co-educational. During Sam McClure's stewardship, the college moved to its new campus in 1985, relocating to the 63 acre (254,952m²) site at Celbridge House on the outskirts of the city. Under Canon Robert John Black, Kilkenny College saw a significant phase of growth, development and expansion to the facilities and resources of the school during his nine years of leadership.

Quarterly: 1st, or, a chief indented, azure; 2nd, gules, quarters: with three covered cups or; 3rd, argent, a lion rampant gules, on a chief of the second a swan, close, of the first, tween two annulets or; 4th, ermine, a saltier gules. Out of a ducal coronet or, a plume of five ostrich feathers, there from issuant a falcon, rising all argent. Dexter, a falcon, wings expanded argent, beaked and membered or; sinister, a male griffin argent, beaked, rayed, collared and chained gold or.