One of the most powerful ideas in Irish genealogy is that surnames have geography. Unlike in more mobile societies, Irish families often stayed rooted in the same townlands and parishes for generations, which means a surname’s distribution across the country is frequently a map of where that family — and its branches — actually lived.
Our Name Distribution tool turns that idea into an interactive map you can explore in seconds.
How it works
Type a surname and the tool plots where it appears across Ireland, shading the map by how concentrated the name is in each area. Dark clusters show the heartlands of a name; scattered lighter areas show where branches settled or migrated. It is an immediate, visual answer to the question every Irish researcher eventually asks: where are we actually from?
The surname Maguire mapped across Ireland — darker areas mark its heartland — with phonetic variants grouped above the map.
Two centuries, side by side
You can switch the underlying data source between Griffith’s Valuation (1848–1864) and the 1901 or 1911 census. Comparing them is revealing: a surname that was tightly concentrated in one barony in the 1850s may have spread along a rail line or toward a city by 1911. Watching a name move across half a century is often the clearest picture you will get of your family’s story between the Famine and independence.
Spelling variants, grouped for you
Irish names were written down by ear. A single family could appear as “Reilly”, “O’Reilly” and “Riley” in different records. The tool groups phonetic variants automatically and lets you choose which spellings to include on the map. That means you can see the true footprint of a family, not just one arbitrary spelling of it.
Zoom in and the heatmap resolves into the individual townlands where the name was recorded.
A surname isn’t just a word — it’s a place on the map. Name Distribution shows you where.
Irish Roots
Turning a map into a lead
When the map points you to a heartland, the next step is to drill in. Head to our Griffith’s Valuation search and filter by the county the map highlighted, then work down to the townland. Distribution tells you where to look; the record sets tell you who was there.