There are approximately 372,905 listed historic buildings in England and 2.5% of these are Grade I. This article comprises a list of these buildings in the county of Cornwall.

Launceston is a town, ancient borough, and civil parish in Cornwall, England, United Kingdom. It is 1 mile (1.6 km) west of the middle stage of the River Tamar, which constitutes almost the entire border between Cornwall and Devon. The landscape of the town is generally steep particularly at a sharp south-western knoll topped by Launceston Castle. These gradients fall down to the River Kensey and smaller tributaries.