With the backdrop of climate change and Ireland’s reliance on fossil fuels, the need to exploit Ireland’s potential for secure, reliable and diverse indigenous renewable energy supply is immediate. The contribution of geothermal energy to the required energy transformation of Ireland has fallen behind targets and is far from realising its full potential. As a guide to geothermal conditions beneath our feet, Ireland’s current maps of temperature within the subsurface are based on unrealistic assumptions and only a few shallow borehole temperature measurements. G.O.THERM.3D proposes a novel approach to quantify and map temperature in Ireland’s crust in an integrated approach that simultaneously accounts for multiple geophysical and petrological datasets. Based on this integrative approach a new 3D temperature atlas for Ireland’s crust will be built from the bottom up. The 3D temperature model will provide an insight into the thermal regime within Ireland’s subsurface, offering a robust constraint on future quantitative modelling of both shallow and deep geothermal prospects across the country. The temperature model and its associated data will be made publicly available for the community on an interactive online platform and the main results will be presented in national and international conferences as well as outreach events to increase public awareness of geothermal energy. The outcomes of this project should assist in the development of public policy on geothermal energy exploration, mapping, planning and exploitation.