From the time Christianity first arrived in Ireland in the second half of the 5th century (in the form of Saint Patrick's mission), the early church was centred on Monastic settlements.

It wasn't until 1874 that the then bishop, Laurence Gillooly, decided to rebuild the cathedral, this time in Sligo town.

[2] In recent years the Diocese has run the Maryvale Institute course in catechism[3] as part of it faith development programmes.

[4] There are currently thirty-seven parishes in the diocese, which are divided into 6 administrative deaneries, based in the towns of Sligo, Boyle, Strokestown, Castlerea, Roscommon and the part of Athlone west of the River Shannon.

[1][5] The following are the parishes of the Diocese of Elphin:[6] Ahamlish-innismurray (Grange and Cliffoney) Ahascragh (Ahascragh and Caltra) Ardcarne (Cootehall) Athleague (Athleague and Fuerty) Athlone, Ss Peter and Paul's Aughanagh (Ballinafad) Aughrim (Aughrim and Kilmore) Ballinameen (Kilnamanagh and Estersnow) Ballintubber (Ballintober and Ballymoe) Ballyforan-dysart-tisrara Ballygar (Killian and Killeroran) Boyle Castlerea (Kilkeevan) Croghan (Killukin and Killummod) Drumcliff & Maugherow Elphin (Elphin and Creeve) Fairymount (Tibohine) Frenchpark (Kilcorkey and Frenchpark) Geevagh Kilbegnet (Glinsk and Creggs) Kilbride (Fourmilehouse) Kilgefin (Ballagh, Cloontuskert and Curraghroe) Kilglass (Kilglass and Rooskey) Kiltoom (Kiltoom and Cam) Knockcroghery / St. John's / Rahara Loughglynn (Loughglynn, Lisacul and Gorthaganny) Oran (Cloverhill) Riverstown Roscommon Rosses Point Sligo, St Anne's & Carraroe Sligo, St Joseph's & Calry Sligo, St Mary's (Cathedral parish) Strandhill/Ransboro Strokestown (Kiltrustan, Lissonuffy and Cloonfinlough) Tarmonbarry Tulsk (Ogulla and Baslic) This article incorporates text from a publication now in the public domain: Herbermann, Charles, ed.