It is dedicated to Saint Cadfan, who founded a clas (ecclesiastical settlement) at Tywyn in the 6th century.

Brut y Tywysogion states that the church was sacked by Vikings in 963, and during the twelfth century it was the subject of a memorable poem by Llywelyn Fardd (I).

The earliest parts of the building date to the twelfth century, and it originally had a central tower, although this fell down in 1693.

The other is a military figure thought to be Gruffudd ab Adda (d. c. 1350) of Dôl-goch and Ynysymaengwyn.

The effigy is known as the 'Crying Knight' due to a flaw in the stone at his right eye which becomes damp during wet weather, giving the impression of weeping.