The church of Heysham is impressively sited on a churchyard that slopes down towards Morecombe Bay. It is of sandstone and has a large single-gable roof over the nave. The tall E and W walls appear to be Saxon, with a blocked Saxon doorway in the W wall. The S arcade may have been the first major expansion of the Saxon church towards a late medieval-fully aisled plan. The N aisle, except for the vestry, is 19thc. The chancel appears, from its fenestration, to be 14thc. The two capitals of the chancel arch may be considered as Romanesque.

Heysham appears in Domesday under the large ploughshares of Preston/Amounderness, held by Earl Tosti and in 1086 King William. The patronage of Heysham church was given to the Abbey of St. Martin, Sées in 1094, but the church was never appropriated, the rector paying 6s. 8d. a year to the Prior of Lancaster. The site clearly has Saxon origins: just above the parish church, on the cliff, is St Patrick's chapel, a ruined site of an 8thc chapel, apparently used as a pilgrimage site to the 10thc. It may be that the chapel was a small monastic community who cared for cult around a supposed landing site of St Patrick on mission from Ireland, and St Peter below had a parochial function.

Cable moulding is a Romanesque motif but the way it is used at Heysham is most untypical of the style as they do not suit the architectural, load-bearing function as capitals. In Romanesque cable is used as a necking or trim, rather than the sole ornamental motif. They are probably from the "Saxo-Norman overlap" of the late 11thc, but in rather isolated north Lancashire 12thc is not impossible.

Although there are a number of Saxon fragments: a hogback tomb in the S aisle, and an excellent base of a churchyard cross, a later medieval cross shaft and a portion of the N wall of the church with a Saxon doorway in the churchyard, no further Romanesque fragments could be located in the vicinity.