St Mary’s Church, Dolgellau, is a Grade II listed building standing on the site of a medieval one, dating back to at least 1254 when it was mentioned in records. The current church is rare (for Wales) being Early Georgian, it was built AROUND the old one, which still continued to hold services. The old church was only demolished when the new one was completed (around 1716-1723) and then the old building was removed from within it.

The font from the original church, built circa 1250, is on display near the entrance. This was placed during the time of John Ellis, who was Rector from 1646-1665 and was also founder of the Dolgellau Grammar School. A chantry alter is recorded as having been located in the church in 1558.

The church contains a 14th century Effigy of Meurig ap Ynyr Fychan, an ancestor of Hywel Sele and the Nanney/Vaughan families of nearby Nannau. This used to lay in the chancel of the old church, but was moved to one of the north windows. A piece of the wall was removed to accommodate his feet. His sword is dated 1723, when the nave was completed.

The nave was constructed using dressed slate stones and the wooden posts were brought over the hills from Dinas Mawddy using oxen. They used to have brass coffin plates nailed to them, which was a custom at the time, but these have now been removed.

The tower was probably begun around 1727. The churchyard was extended to the north-west by ten roods in 1792.

There was also major restoration in 1864 and the chancel arch dates to this time. A central window was inserted in 1901.

The upper room (on the western end) was added in 1992 by Roy Olsen of Dolgellau. It is bow-fronted with arched windows.