Care home residents were vulnerable to severe effects from Covid-19 infection and experienced high mortality, especially early in the pandemic. In response, many countries introduced visiting restrictions to limit transmission. These often proved extensive and prolonged, drawing fresh attention to issues of autonomy and human rights in long-term care. We conducted in-depth interviews with 27 family carers in England with relatives living in a care home during the pandemic. Adopting a relational autonomy lens, conceptualised using the capability approach, we examined how family carers considered their relatives’ capabilities to have been impacted by visiting restrictions and how relational support could be strengthened. Family carers were concerned for their relative’s fundamental capabilities, including physical health, emotional well-being, and feeling connected to significant others. Capability deprivations were associated with family separation, ‘adapted’ visits that were inappropriate for their relative’s needs, and lack of opportunity for family carers’ to provide emotional support, help staff identify their relative’s emotional and physical needs, monitor care standards or advocate for their relative. Optimising relational support during a public health emergency requires effective collaboration between care homes and family carers. Specific measures include (1) ensuring there is clarity, a sense of shared purpose, clear accountability and confidence in visiting restrictions, (2) providing family carers regular, personalised updates about their relative using a range of digital communication tools, (3) allowing choice about visiting arrangements where possible, and ensuring visits are appropriate for residents with dementia and (4) ensuring that family carers feel welcomed, involved and enabled to resume in-person visits at the earliest opportunity. Consultation with care homes, families and residents, and workforce and digital readiness should be prioritised.