Family relationships play a major role in individuals' lives and can be a source of comfort, support and protection during the entire lifecourse. Particularly in the context of life events, such as widowhood, family relationships may be salient for (older) adults in coping with feelings of grief, loss and loneliness. Using Dutch survey data and 18 in-depth interviews from a sub-sample, this study examines the role of family relationships through the lifespan in reducing loneliness among ever-widowed older adults (i.e. persons who have at some time during their life experienced the death of a spouse). Particular attention was paid to childhood memories, family ties and support from siblings. Quantitative analyses examined associations between loneliness and childhood experiences of relationships with parents, family ties and sibling support. Qualitative data elucidated how ever-widowed adults recall relations with parents and siblings and experience current family relations. Quantitative and qualitative data showed that emotional support from siblings reduced loneliness. Additionally, positive memories of childhood relationships and current family ties were negatively related to loneliness. In times of ever-increasing longevity, work detailing how family relationships across the lifecourse are supportive in alleviating loneliness is a key issue on the social research and policy agenda.