The Cathedral Church of St Flannan, Killaloe (/ˌkɪləˈluː/ kil-ə-LOO) is a cathedral of the Church of Ireland in Killaloe, County Clare in Ireland.

[1] On the north side of the cathedral is a small oratory or chapel (8.78 X 5.33 m (28ft 9 in X 17ft 6 in)[2] of a date earlier than the cathedral; and probably the original sanctuary of the holy man who founded the abbey.

Its roof is very deep, and made entirely of stone; it has a belfry, and two doorways to the east and west.

[4] A £200,000 restoration project involving the repair of a Romanesque doorway and the reconstruction of a 12th-century high cross, was completed in 2001.

The Kilfenora Cross, embedded in the walls of the Gothic cathedral in the 1930s, is once again free-standing.