Europe’s aging population increasingly faces social isolation and loneliness, with nearly 20% of older adults living alone. Social isolation refers to an objective lack of social contact, while loneliness is the subjective experience of unmet social needs. Both are prevalent among community-dwelling older adults, driven by life transitions, loss, and declining health. These issues severely impact mental and physical health, increasing risks of depression and suicidal ideation. This scoping review maps the literature, identifies knowledge gaps, and highlights key challenges regarding loneliness and social isolation in this population. A scoping review was conducted between March and September 2024, following the PRISMA guidelines for scoping reviews. The review adhered to Arksey and O’Malley’s five-stage framework, which includes identifying research questions, searching for and selecting relevant studies, extracting data, and synthesizing results. The search was conducted in major scientific databases, including Embase, CINAHL Plus, Web of Science, and PsycINFO, along with grey literature sources, including doctoral theses and organizational reports. A total of 45 studies were included, with 66.6% using quantitative methods, 11.1% using qualitative methods, and the remainder being systematic reviews or mixed-method analyses. The studies revealed a significant prevalence of loneliness and social isolation among community-dwelling older adults, with risk factors including health deterioration, widowhood, and loss of social networks. The consequences of loneliness and isolation span physical and mental health issues, including an increased risk of cardiovascular disease, anxiety, depression, and cognitive decline. Loneliness and social isolation among community-dwelling older adults are complex issues with profound implications for physical, mental, and social well-being. Addressing these challenges requires integrative approaches that consider individual, relational, and contextual factors. Further longitudinal and standardized research is needed to improve our understanding of the long-term impacts and effectiveness of interventions to mitigate these issues.