The church was formerly a chapel of ease to Llanbeulan church, which stands 1½ miles to the N. St Mary's has a small medieval nave, but with later door and windows; chancel rebuilt in the 16thc and a S chapel added in the 17thc. The 12thc font was the only Romanesque carving when the church was visited, but it was moved to Llanfaelog church in the following year when Talyllyn was made redundant. Since it was recorded and photographed before that date it appears in the Talyllyn entry here.

RCAHMW described the motif on the N face as an "expanded-arm cross on short shaft". The shaft however would be horizontal, and two oblique lines are left unaccounted for.