Ardagh
- Ardagh (barony)
- Ardagh (surname)
- Ardagh Castle Cheese
- Ardagh Fort
- Ardagh GAA
- Ardagh Group
- Ardagh Hoard
- Ardagh railway station
- Ardagh, County Antrim
- Ardagh, County Donegal
- Ardagh, County Limerick
- Ardagh, County Longford
- Ardagh, County Mayo
- Ardagh–Johnson Line
- Diocese of Kilmore, Elphin and Ardagh
- List of townlands of County Londonderry
- List of townlands of County Sligo
- List of townlands of the barony of Bear
- Roman Catholic Diocese of Ardagh and Clonmacnoise