A just energy transition requires not only the achievement of low-carbon goals but also the creation of fairer energy systems where special attention is given to identifying vulnerable groups and addressing the inequalities they experience. Governing energy transitions at the regional level may help formulate and implement tailored policies addressing vulnerabilities at the local level. However, there is limited understanding of the vulnerabilities that citizen groups experience in energy regions. We formulated three objectives to address this gap: I) identifying energy vulnerabilities in a regional transition context; II) understanding what citizen groups experience them and why; and III) identifying barriers that prevent policies from engaging with these groups. We applied a case-study research design to the Rotterdam-The Hague energy region in the Netherlands. Data collection involved semi-structured expert and stakeholder interviews and a review of newspaper articles and policy reports. We processed data with a thematic analysis drawing from energy justice literature and intersectionality theory. Three main energy vulnerabilities were identified: unaffordability of energy consumption, the lack of opportunity to own self-generation technology, and little to no inclusion in decision-making processes. The findings reveal five groups prone to vulnerability and the conditions that put them in a vulnerable situation, such as living in an energy-inefficient house. We conclude that regional energy transition policies should consider intersections of society while offering more support to municipalities to enable them to engage citizen groups at higher risk of energy vulnerability.