St Hilary is situated in the Deanery and Hundred of Penwith. It is bounded on the North by St Erth, on the East by Breage and Germoe, on the South by Perranuthnoe and the ocean, and on the West by Ludgvan. The parish of Marazion was created from part of this parish in 1813, but the civil parish of St Michael's Mount has always remained part of this parish ecclesiastically.