Morgan's Hill Enclosure is an archaeological site in Wiltshire, England, on Morgan's Hill south-east of Calne, about 130 metres (430 ft) north of the Wansdyke. It is a scheduled monument.

The earthwork is a square, aligned west–east, with sides of length 180 metres (590 ft) enclosing an area of about 3.25 hectares (8.0 acres)), with a bank of height up to 0.6 metres (2 ft 0 in) and width about 3 metres (9.8 ft). Outside the bank is a ditch of width about 4 metres (13 ft) and depth up to 1 metre (3 ft 3 in). There are three entrances around the rectangle, but it is not known if these are original.

There was some excavation in 1909: some medieval pottery was found at the surface, but nothing was found that could clearly relate to its original construction.

Enclosures like this are considered to show evidence of agricultural practices, from the Neolithic period to the Romano-British period; they were stock pens or protected areas for crops. Several comparable enclosures are known in the area of the Avebury prehistoric complex, about 4 miles (6.4 km) to the east, which was in use in the Neolithic period and early Bronze Age.

• List of prehistoric structures in Great Britain