Research capacity building in social care has received increased attention and dedicated funding in recent years, yet opportunities for practitioners to engage with research or apply evidence-based practice remain limited. This article evaluates one mechanism for developing capacity through a research-practice partnership: funding and supporting social care staff to undertake practitioner-research fellowships. This qualitative study incorporated interviews with fellows, applicants, mentors, line managers, and experts by experience; focus groups with academic supervisors and programme leads; and reviews of progress reports. Using thematic analysis, it identified three themes: challenges in applying for and undertaking fellowships, and partnership support that helped address them; the impacts of fellowships on social care practitioners and organizations; and lessons learned at individual, team and system levels, including the importance of engaging middle managers, creating a supportive academic environment, and widening access across a diverse social care workforce. Although research capacity building in social care remains in its infancy, fellowships provide valuable opportunities to nurture practitioner-researchers and foster a research culture. They enable two-way learning between practice and academia, bridging the research–practice gap. However, questions remain around sustainability, inclusivity, and long-term pathways for practitioner-researchers, highlighting the need for continued investment, infrastructure, and flexible models of support.