The Water Newton Treasure is a hoard of fourth-century Roman silver, discovered near the location of the Roman town of Durobrivae at Water Newton in the English county of Cambridgeshire in 1975. The hoard consisted of 27 silver items and one small gold plaque. Because of inscriptions found on some of the pieces in the collection it has been suggested that they may have been used in a local church, and they therefore comprise the earliest probable group of Christian liturgical silver yet found in the Roman Empire.

A hoard or "wealth deposit" is an archaeological term for a collection of valuable objects or artifacts, sometimes purposely buried in the ground, in which case it is sometimes also known as a cache. This would usually be with the intention of later recovery by the hoarder; hoarders sometimes died or were unable to return for other reasons before retrieving the hoard, and these surviving hoards might then be uncovered much later by metal detector hobbyists, members of the public, and archaeologists.