Ageing populations in the Asia-Pacific region face numerous challenges, among which social isolation and loneliness are becoming a significant public health concern. Social isolation, commonly defined as the absence of social integration and feeling of disconnection, is often experienced together with loneliness, despite being distinct concepts. These conditions significantly affect older adults’ health in both community and institutional settings. The complex and varied nature of social isolation and loneliness, their prevalence, risk and protective factors, consequences, and possible interventions are described in this chapter. This chapter also explores the key risk and protective factors categorized into four major domains including health, cognitive and psychological, sociocultural, and environmental factors. Addressing these public health concerns necessitates integrated interventions using the socio-ecological framework targeting individual, interpersonal, community, and societal levels. To effectively deliver interventions across multiple levels, interventions are either delivered in-person or via technology. Promising solutions can help to create a supportive network that can help combat loneliness, improve the well-being of older adults and promote a more inclusive society in the Asia-Pacific region.