Dementia Care Networks (DCNs) provide essential support for persons with dementia (PWD) and caregivers, yet research on informal support within regional DCNs remains limited. This study explores informal support at regional DCN, examining facilitators and barriers within DCNs in southeastern Germany. An exploratory-descriptive qualitative approach was used, incorporating semi-structured interviews and participant observation with 23 individuals, including social workers, physicians, nurses, volunteers, family caregivers, and PWD across two Bavarian communities. A thematic content analysis was first conducted to code and analyze the interviews. Subsequently, a structured content analysis, guided by the Social-Ecological Model, was applied to identify facilitators and barriers at individual, interpersonal, organizational, community, and regional levels. Our study identified four types of informal support benefiting family caregivers, PWD, and formal service providers:1) support for family caregivers; 2) support for formal service providers; 3) person-centered one-to-one support for PWD. Key facilitators include increased dementia awareness, networking platforms, strong volunteer traditions, supportive policies, and collaboration among network leaders. Additionally, an unexpected spill-over effect contributed to sustaining informal support by enhancing community well-being and supporting former caregivers. However, sustainability of DCN is challenged by organizational and institutional barriers, such as limited awareness and stakeholder competition. Findings underscore informal support’s critical role in bolstering family resilience amid strained formal care systems, offering actionable insights for optimizing DCN efficacy in resource-constrained settings.