PilotSTRATEGY focuses on advancing understanding of deep saline aquifer (DSA) resources for geological CO2 storage in five European industrial regions in Southern and Eastern Europe. DSAs have much promise and potential for CO2 storage, but despite their high potential storage capacity, they are not well studied. There is a need to increase confidence and maturity of understanding of these sites. PilotSTRATEGY will investigate DSA in detail in three regions of Southern Europe: Paris Basin (France), Lusitanian Basin (Portugal) and Ebro Basin (Spain). This will include acquisition of new data, detailed geo-characterisation, feasibility studies and preliminary design or pre-front end engineering and design studies. At the end of the project, the level of site characterisation in these three regions will be sufficient to allow a final investment decision to be made and for storage permitting and project approval to be obtained. In two further regions of Eastern Europe, West Macedonia (Greece) and Upper Silesia (Poland), PilotSTRATEGY will increase the maturity and confidence level of understanding of DSA storage resources, based on new available data, reprocessing of old data and new dynamic simulation studies. This will enable these regions to start planning to develop their storage resources. Recognising the social challenge of implementing geological CO2 storage, PilotSTRATEGY will take a systemic approach and analyse the factors that influence societal acceptance of storage sites, to develop methods for societal engagement. Regional stakeholders and the local public will be involved in developing recommendations and concepts as part of the pilot conceptualization and design. At the same time, PilotSTRATEGY will run a series of dialogues, “Talk with Authorities,” to support capacity building in local authorities and build policy makers’ awareness of geological CO2 storage, particularly the role of CCUS in just, net-zero transitions in all regions.