Mayo County Council
Ireland's local authority for County Mayo, responsible for planning, housing, roads and water services.
On 17 September, An Coimisiún Pleanála overturned Mayo County Council’s 2025 planning permission for a €1.5bn Killala data centre, leaving the site without permission.
Last refreshed: 24 September 2026
Timeline for Mayo County Council
Ireland refuses €1.5bn Mayo data centre
Data Centres: Boom and BacklashBackground
Mayo County Council is the local authority for County Mayo in western Ireland. Its REMIT covers planning, housing, roads, water services, fire services, libraries, waste management, and community and economic development. These duties make it the public body responsible for local services and development decisions across the county.
Planning is central to how the council shapes long-lived development in a rural county. Its 2025 permission for the Killala data-centre proposal was overturned by An Coimisiún Pleanála on 17 September 2026, illustrating that council planning decisions can be reviewed through Ireland’s national appeals system. The council’s wider role remains to weigh development proposals alongside infrastructure and public-service duties.
Mayo County Council’s grant was overturned
On 17 September, An Coimisiún Pleanála refused planning permission for the proposed €1.5bn Killala data centre. Its decision overturned Mayo County Council’s 2025 grant after the developer failed to show a fixed grid connection agreement or a renewable power purchase agreement.
For Mayo County Council, the ruling reverses a major planning decision in one of its core statutory functions. The Killala site has no planning permission after The National appeals body’s refusal, rather than the local consent granted in 2025.