St. Mary's Collegiate Church is among the oldest medieval churches which is still in use in Ireland. Although a church has been on the site for over a thousand years, the present structure dates from around the 1220's.

St. Mary's Collegiate Church is among the oldest medieval churches which is still in use in Ireland. Although a church has been on the site for over a thousand years, the present structure dates from around the 1220's.

It is situated in perhaps the most visibly historic part of the town with Myrtle Grove to its right, the town walls to its rear and St. Mary's College & gardens to its left. Parish accounts for Youghal can be dated in the Vestry Book to 1201 while Pope Nicholas IV described Youghal as the richest town in the local dioceses of Cloyne. 

Inside the church itself, the East window dates from 1498 when the Eight Earl of Desmond added a new chancel to the Church. 

In the south wing is also the tombstone and grave of Richard Boyle (1566-1643), first Earl of Cork. The carvings show himself, his three wives and sixteen children. 

Surrounding the church is the ancient graveyard with the town walls situated on the rising ground to the rear.