The COVID-19 pandemic has in many ways challenged the health and well-being of people, and more widely, the welfare systems in the Nordic countries. Due to regulations and lockdowns, many people have experienced social isolation, and certain vulnerable groups – such as older adults and those with disabilities – have been hit especially hard. As loneliness has implications for people’s long-term mental and physical health, the consequences of the pandemic are significant for health and social care as a whole.This literature review describes the impact of the COVID-19 pandemic on loneliness and social isolation among younger and older adults living in the Nordic countries, with and without disabilities, and in different situations.