St Tudwal's Church is situated within a curvilinear churchyard on the north shore of Milford Haven. Llanstadwell was alientated by Bishop Wilfrid of St Davids between 1085 and 1115, having previously been an episcopal possession. The church was a parish church during the medieval period, belonging to the Deanery of Rhos when it was an appurtenant to Haverfordwest Priory. At the dissolution the paronage of Llanstadwel, along with the appurtances of Haverfordwest Priory, fell to the Crown. In 1545the rectory (with other rectories) was leased to Henry Jones of the royal household for 21 years. The rectory was owned by William Walter of Roch in 1610. It later passed to the Allen family, and thereafter to a variety of individuals.

The church is medieval construction is in unsquared, uncoursed, large limestone rubble without quoins; beneath thick lime render dating from the 18th century. The 18th century stonework is similar, but often quoined and has extensive repointing. The church consists of 2-bayed chancel, wider 4-bayed nave, north transept, south transept, north porch, 3-storeyed west tower , and vestry/boilerhouse (against the chancel and south transept walls). The square font bowl is 12th to early 13th century in date. The nave, chancel north transept and tower are fundamentally medieval, but were raised by around 1m in 1876, burying lower portions of walls and floors. The chancel may have original been Romanesque. The north transept may have been added in the 14th century. There is a former choir recess against the chancel north wall, probably dating from the 14th ?15th century. The 3-storeyed tower, which tapers slightly and has the basal batter typical of the district, was added around 1500. The church was restored in 1876, when the south transept and porch were added, and the nave was reroofed and refloored. The current 2-centred chancel arch dates to this time. All internal fittings date to the later 20th century.

Sources include:
Cambria Archaeology, 2000, Carmarthenshire Churches, gazetteer, 48
Cambria Archaeology, 2003, Early Medieval Ecclesiastical Sites Project, Pembrokeshire gazetteer

N Vousden, 8 January 2018