The architect of the Victorian reconstruction was Samuel Pountney Smith, who retained little of the earlier church, with the exception of the tower.

The churchyard contains the grave of the Ladies of Llangollen, Eleanor Charlotte Butler and Sarah Ponsonby, and their servant Mary Carryl, who lived at the nearby Plas Newydd.

Collen was a monk from Glastonbury who is reputed to have arrived in Llangollen in a coracle and founded the first church on the site in the 6th century.

[6] In the early 19th century, the church was the place of worship of Eleanor Butler and Sarah Ponsonby, the Ladies of Llangollen, whose house, Plas Newydd, was situated just outside of the town.

[5] The tower has four storeys[5] and the architectural historian Edward Hubbard, in his 2003 Clwyd volume of the Pevsner Buildings of Wales, records its urn-like pinnacles.

[8] The internal hammerbeam roof in the nave has elaborate wood carving and is reputed to have been brought from Valle Crucis Abbey, but both Cadw and Hubbard doubt this attribution.

[5] The church contains an important series of Victorian stained glass by, among others, Alexander Gibbs, Done & Davies[5] and William Holland.

[15] Eleanor Butler and Sarah Ponsonby met in 1768 and left their native Ireland a decade later to escape the threat of forced marriages.