The Chiltern Hills are a chalk escarpment that stretches in a south-west to north-east diagonal across several counties of southern England, but is most prominent in Buckinghamshire. The ridge overlooks the Vale of Aylesbury, and approximately coincides with the southernmost extent of the ice sheet during the last ice age. The Chilterns are part of the Southern England Chalk Formation which also includes Salisbury Plain, Cranborne Chase, the Isle of Wight and the South Downs.

Its highest point is at Coombe Hill near Wendover. A prominent hill is the nearby Ivinghoe Beacon, the starting point of the Icknield Way and The Ridgeway long distance path, which follows the line of the Chilterns for many miles to the west, where they merge with the Wiltshire downs and southern Cotswolds. To the east of Ivinghoe Beacon is Dunstable Downs, a steep section of the Chiltern scarp that is the site of the famous London Gliding Club and Whipsnade Zoo.

The more gently sloping country to the south of the Chiltern scarp is also generally referred to as The Chilterns, containing much Beech woodland and many pretty villages. Due to the quality hardwood, the area was once renowned for its chair making industry, centred on the town of High Wycombe.

This area is also known as the Chiltern Hundreds, an administrative area of convenience used to subvert an archaic rule, which permits a member of parliament, who is not allowed to resign, to apply for tenureship of the Chiltern Hundreds, thus relieving him of his parliamentary duty.

Rivers that drain from the Chiltern Hills include the River Lee, River Ver, River Bulbourne and River Gade .

List of notable towns and villages in, and adjacent to, the Chilterns

• Aldbury
• Amersham
• Apsley
• Ashridge
• Aylesbury
• Beaconsfield
• Berkhamsted
• Bovingdon
• Chalfont St Giles
• Chesham
• Cholesbury
• Chinnor
• Dunstable
• Edlesborough
• Ellesborough
• Great Missenden
• Halton
• Hawridge
• Hemel Hempstead
• High Wycombe
• Hitchin
• Jordans
• Leighton Buzzard
• Luton
• Princes Risborough
• Stokenchurch
• Studham
• Tring
• Wendover
• Whipsnade