St Dennis (Cornish: Tredhinas) is a civil parish and village in Cornwall, England, United Kingdom. The village is situated on the B3279 between Newquay and St Austell.
St Dennis had a population of 2,696 in the 2001 census, increasing to 2,810 at the 2011 census. An electoral ward also exists with a population at the same census of 4,560. A quarter of the male population is employed in the extraction of china clay.