Freston is a Neolithic causewayed enclosure, an archaeological site near the village of Freston in Suffolk, England. Causewayed enclosures were built in England from shortly before 3700 until at least 3500 BC; they are characterised by the full or partial enclosure of an area with ditches that are interrupted by gaps, or causeways. Their purpose is not known; they may have been settlements, meeting places, or ritual sites.
The Freston enclosure was first identified in 1969 from cropmarks in aerial photographs. At 8.55 ha (21.1 acres) it is one of the largest causewayed enclosures in Britain, and would have required thousands of person-days to construct. The cropmarks show an enclosure with two circuits of ditches, and a palisade that ran between the two circuits. There is also evidence of a rectangular structure in the northeastern part of the site, which may be a Neolithic longhouse or an Anglo-Saxon hall. In 2018, a group from McMaster University organized a research project focused on the site, beginning with a geophysical survey and a pedestrian survey to collect any items of archaeological interest from the surface of the site. This was followed by an excavation in 2019 which recovered some Neolithic material and obtained radiocarbon dates indicating that the site was constructed some time in the mid-4th millennium BC. Other finds included oak charcoal fragments believed to come from the palisade, and evidence of a long ditch to the southeast that probably predated the enclosure, and which may have accompanied a long barrow, a form of Neolithic burial mound. The site has been protected as a scheduled monument since 1976.