Away from the coast, St Gennys parish is entirely rural. It is bordered to the north by Poundstock parish, to the east by Jacobstow parish, to the south by Otterham and St Juliot parishes.
To the west, St Gennys is bounded by the Atlantic coast where Cornwall’s highest cliff (appropriately named High Cliff) rises 735 feet (224 m) above the rocky foreshore. Cambeak is a prominent headland and the cliffs at the Strangles are a National Trust property. In one year in the 1820s it is believed 23 ships were wrecked on this part of the coast.