The Ardagh Hoard, best known for the Ardagh Chalice, is a hoard of metalwork from the 8th and 9th centuries. Found in 1868 by two young local boys, Jim Quin and Paddy Flanagan, it is now on display in the National Museum of Ireland in Dublin. It consists of the chalice, a much plainer stemmed cup in copper-alloy, and four brooches — three elaborate pseudo-penannular ones, and one a true pennanular brooch of the thistle type; this is the latest object in the hoard, and suggests it may have been deposited around 900 AD.

The chalice ranks with the Book of Kells as one of the finest known works of Insular art, indeed of Celtic art in general, and is thought to have been made in the 8th century AD. Elaborate brooches, essentially the same as those worn by important laypeople, appear to have been worn by monastic clergy to fasten vestments of the period.