This is a list of Grade I listed buildings in Wiltshire, England, in the United Kingdom.
These buildings are protected for their historic significance. At present, there is a parallel system for ancient monuments, known as 'scheduling', which means that there is not a consistent approach to sites like castles, abbeys and henges which can be listed, scheduled or both. Should the draft Heritage Protection Bill become law, the systems will be merged into a single Register of Historic Buildings and Sites of England, which will also subsume various other existing registers. In England, the listing is administered by English Heritage, an agency of the government's Department for Culture, Media & Sport — under the new legislation they will become officially responsible for the designation.
Buildings of outstanding architectural or historic interest are listed at Grade I — of the approximately 372,905 listed buildings in England, over 9,000 (2.5%) are Grade I. Estimates to the numbers of buildings do, however, vary given that listings are for what are structurally separate buildings: therefore a street of houses can be listed as one building, but a church wall can be listed separately from the church. Some buildings are listed for group value.
This list is of the nearly 300 Grade I listed buildings in the ceremonial county of Wiltshire, by former district. There is a characteristically large contribution from Church of England (Anglican) parish churches, and several great English country houses are included with some of their landscaping features. Several barns are included and Crofton Pumping Station is associated with water supply.