Buckinghamshire (abbreviated Bucks) is one of the home counties in South East England. The county town is Aylesbury.

The area under the control of Buckinghamshire County Council, or shire county, is divided into four districts - Aylesbury Vale, Chiltern, South Bucks and Wycombe. Milton Keynes is a unitary authority and forms part of the county for various functions such as Lord Lieutenant but does not come under county council control. The ceremonial county, the area including Milton Keynes, borders Greater London, Berkshire, Oxfordshire, Northamptonshire, Bedfordshire and Hertfordshire.

The county includes the Chiltern Hills to the South and the Vale of Aylesbury to the north. At 876 feet (267 m) above sea level, the two highest points are Coombe Hill near Wendover, and Haddington Hill in Wendover Woods, Buckinghamshire, near Wendover where a stone marks the summit.

The name Buckinghamshire is Anglo Saxon in origin and means The district (scire) of Bucca's home. Bucca's home refers to Buckingham in the north of the county, and is named after an Anglo-Saxon landowner. The county has been so named since about the 12th century; however, the county itself has existed since it was a subdivision of the kingdom of Mercia (585-919).

The history of the area though predates the Anglo Saxon period and the county has a rich history from the Celtic through to Roman periods though the Anglo Saxons did have perhaps the greatest impact on Buckinghamshire out of these groups: the geography of the rural county is largely as it was in the Anglo Saxon period. Later Buckinghamshire became an important political arena, with King Henry VIII intervening in local politics in the 16th century and just a century later the English Civil War was reputedly started by John Hampden in mid-Bucks.