Causewayed enclosures are a type of large prehistoric earthworks common to the early Neolithic in southern Britain. Examples are also known further north and similar sites are known from Scandinavia to France.

Causewayed enclosure is preferred to the term causewayed camp as it has been demonstrated that the sites did not necessarily serve as occupation sites.

They are often hilltop sites, encircled by between one and four segmented concentric ditches, with an internal bank, also segmented. Crossing the ditches at intervals are causeways which give the monuments their names. It appears that the ditches were excavated in sections, leaving the wide causeways intact in between. They should not be confused with segmented, or causewayed ring ditches, which are smaller and relate only to funerary activity or with hillforts which are later and had a definite defensive function.

Archaeological evidence implies that the enclosures were visited occasionally by Neolithic groups rather than being permanently occupied. It is possible that they represent a transitional period in the Neolithic before hunter-gatherer societies finally became fully settled. The presence of human remains in the banks and ditches of the enclosures has been seen as an attempt by the builders to connect their ancestors with the land and thus begin to anchor themselves to specific areas.

In the 1970s the archaeologist Peter Drewett suggested seven possible functions for the sites:

• Settlement
• Defence
• Cattle compounds
• Trade centres
• Communal meeting places
• Cult/ritual centres
• Burial sites

(to which must be added the more recent idea that they were also used as landmarks)

Animal remains, domestic waste and pottery have been found in at the sites but only limited evidence of any structures. Generally, it appears that the ditches were permitted to silt up, even while the camps were in use, and it is unlikely that they had a strong defensive purpose. It may be that the earthworks were designed to keep wild animals rather than people out. The sequential addition of second, third and fourth circuits of banks and ditches may have come about through growing populations adding to the significance of their peoples' monument over time. In some cases, they appear to have evolved into more permanent settlements.

Examples of causewayed enclosures include those at Hambledon Hill, Windmill Hill, Hembury and Coombe Hill. Some tor enclosures such as that at Carn Brea are believed to have served a similar purpose in south western Britain.