question: There has been growing recognition of the harmful consequences of loneliness for health and well-being, and the need for community intervention, particularly in times of global crisis such as the Covid-19 pandemic with its imperatives of distancing, isolation, and quarantine. Social capital and a sense of social cohesion are known to have roles in buffering against the effects of adverse life circumstances. Our study sought to investigate the association of a range of social attitudes and activities - as proxies for social capital - with loneliness while taking into account socio-demographic factors. We undertook a national survey on a stratified random sample of the New Zealand (NZ) adult population aged 18+ in 2017 (n = 1,358), data from which included the requisite variables. The prevalence of loneliness was highest in young adults (18-30), falling with age until a slight rise in older people (76+). Loneliness was associated with socio-demographic factors, being more prevalent in the more disadvantaged groups: the deprived, Maori (the indigenous people of NZ), the non-partnered, and the less educated. Controlling for these socio-demographic factors, pro-social attitudes (that is towards political efficacy, trust in others, not feeling exploited, or being committed to family) and participation in social activities (that is being employed or being involved in recreation groups) - were protective against loneliness. Our study supports asset-based approaches to tackling loneliness - with implications for health and social care - that emphasise mobilising existing social resources, building social capital, and raising social cohesion in our communities. Such intervention on loneliness would help to prevent and ameliorate its detrimental consequences for public health.