Ireland has a dramatic and unusual population history, with overall population declining dramatically from 8.2 million to 6.5 million between 1841 and 1851 and then declining gradually and almost continuously to 4.5 million in 1961. However, most attempts to understand long-term population change in Ireland have been made at a national scale. Those that have examined the uneven spatial imprint of long-term population change have tended to do so at crude spatial scales. In an attempt to redress this issue, Irish population change data for 160 years of Irish population history have been assembled in an interactive online atlas through which population change at a consistent set of 3432 electoral divisions (EDs) combining Irish and Northern Irish data can be examined. This article focuses on a description of the atlas paying attention to the manner in which data were collected and assembled; the use of the atlas as a resource that encourages and facilitates greater public engagement with the spatiality of population change in local areas; the perspectives gleaned from an initial mapping of long-term population change; and an outline of ways in which the data can be used for academic research.