St Mary's Cathedral, Elphin,[1] is a former cathedral in Ireland.

[2] It was formerly the cathedral of the Diocese of Elphin,[3] and then a joint cathedral in Kilmore, Elphin and Ardagh.

[4] It was founded by St. Patrick and destroyed during the Rebellion of 1641.

[5] It was rebuilt during the time of Bishop John Parker.

[6] It has lain ruined since 1957.