Knole (/noʊl/) is an English country house and former archbishop's palace owned by the National Trust. It is situated within Knole Park, a 1,000-acre (400-hectare) park located immediately to the south-east of Sevenoaks in west Kent. The house ranks in the top five of England's largest houses, under any measure used, occupying a total of 4 acres (16,000 m²; 170,000 sq ft).

The current house dates back to the mid-15th century, with major additions in the 16th and, particularly, the early 17th centuries. Its Grade I listing reflects its mix of late-medieval to Stuart structures and particularly its central façade and state rooms. In 2019, an extensive conservation project, "Inspired by Knole", was completed to restore and develop the structures of the buildings and thus help to conserve its important collections. The surrounding deer park has also survived with varying degrees of management in the 400 years since 1600.

Knole is located at the southern end of Sevenoaks, in the Weald of west Kent. To the north, the land slopes down to the Darenth valley and the narrow fertile pays of Holmesdale, at the foot of the North Downs. The land around Sevenoaks itself has sandy soils, with woodland that was used in the Middle Ages in the traditional Wealden way, for pannage, rough pasture and timber. The Knole estate is located on well-drained soils of the Lower Greensand. It was close enough to London to allow easy access for owners who were involved with affairs of state, and it was on "sounde, parfaite, holesome grounde", in the words of Henry VIII. It also had a plentiful supply of spring water.

The knoll of land in front of the house gives it a sheltered position. The wooded nature of the landscape could provide not only timber but also grazing for the meat needs of a grand household. Moreover, it made an excellent deer park, being emparked before the end of the 15th century. The dry valley between the house and the settlement of Sevenoaks also makes a natural deer course, for a combined race and hunt between two dogs and fallow deer.

There is evidence of the prehistoric at Knole but, as is the case for the surrounding area, no Roman. Much was going on in and around Sevenoaks in the medieval period and major landowners included Roger Bigod and then Otho de Grandison who moved abroad, his estates being broken up. It may be then that the Manor of Knole became a separate entity as the earliest reference to it currently known was not until 1364. In 1419, the estate, which then spread over 800 acres, had been bought by Thomas Langley, Bishop of Durham, and by 1429, he had extended it to 1,500 acres. The estate remained in the hands of the Langley family, it seems, until the mid-1440s when it had been acquired by James Fiennes, 1st Baron Saye and Sele. The circumstances of this transfer are not known, but it is clear that Lord Saye and Sele was also enlarging the estate by further, sometimes forcible, purchases of adjoining parcels of land. For example, in 1448 one Reginald Peckham was forced to sell land at Seal (at the north-eastern end of the current estate) to Saye "on threat of death". Forcible land transfers recur in the later history of the house, including that between Archbishop Thomas Cranmer and Henry VIII.

Lord Saye and Sele seems to have begun a building project at Knole, but it was incomplete by his death in 1450. His ruthless exploitation of his powerful position in Kent was a motivating factor in the Jack Cade Rebellion. Saye and Sele was executed on the authority of a hastily assembled commission initiated by Henry VI in response to the demands of Cade's rebels when they arrived in London.

James Fiennes's heir, William, second Baron Saye and Sele, sold the property for 400 marks (£266 13s 4d) in 1456 to Thomas Bourchier, Archbishop of Canterbury. He already had a substantial property in the area, Otford Palace, but the drier, healthier site of Knole attracted him. Archbishop Bourchier probably began building work by making substantial renovations of an existing house. Between 1456 and 1486, Bourchier and his bailiff for the Otford bailiwick, John Grymesdyche, oversaw substantial building work on the current house. The remodelled house must have been suitable for the archbishop by 1459, when he first stayed there, but he based himself there increasingly in his later years, particularly after 1480, when, at the age of about 69, he appointed a suffragan. In 1480, Thomas Cardinal Bourchier, as he had become in 1473, gave the house to the Archdiocese of Canterbury.

In subsequent years, Knole House continued to be enlarged, with the addition of a large courtyard, now known as Green Court, and a new entrance tower. These were long thought to be the work of one of Bourchier's successors, but the detailed study by Alden Gregory suggests that Bourchier was responsible. He took advantage of the political stability that followed the restoration of Edward IV in 1471 to invest further in his property.