The parish church of St Just stands in the centre of town on a site of Christian worship dating back to the 5th or 6th century. The current building is largely 15th century Perpendicular Gothic, built from local granite — the same material as the town's walls and farmsteads. The tower is squat and powerful, a typical west Cornish form built to withstand Atlantic weather.
The church's most notable contents are two fragmentary medieval wall paintings, discovered in the 20th century when later plasterwork was removed. One depicts a Christ in Majesty; both are faded but clearly readable. Medieval wall paintings are rare survivals in Cornwall, where the Reformation and subsequent enthusiasm for whitewash were especially thorough. The churchyard is large and contains memorials going back several centuries, including memorials to miners killed in the surrounding mines.