Objectives The COVID-19 pandemic shed light on rooted social inequalities and on housing as a crucial social determinant of health. Little is known on current practices and new opportunities to support people experiencing homelessness in a situation of a global health crisis. This study explores frontline workers’ experiences of providing essential services to people experiencing homelessness in Copenhagen, Denmark, during the first COVID-19 lockdown, and highlights best practices of care in future crises. Methods Semi-structured interviews were conducted in August–September 2020 with nine service providers working in six organizations offering essential services to people experiencing homelessness during the spring 2020 lockdown in Copenhagen. The data analysis, following inductive coding, drew upon the concept of disaster resilience. Results Several initiatives were undertaken by the municipality and local organizations to ensure the continuation and adaptation of essential services to people experiencing homelessness during the COVID-19 crisis. These included collaborations with and financial support from businesses, the municipality, and other service providers; a mobile test unit, temporary shelters, and isolation sites; and an increased availability of opioid substitution treatment. Several improvements are to be made, particularly regarding sustainability and long-term benefits of the initiatives, facility-level risk preparedness, universal access to essential services for undocumented migrants, as well as collaboration between service providers. Conclusions The lockdown offered the opportunity to experiment with innovative ways of working, of which many had a protective effect on people experiencing homelessness. This knowledge can be used to improve services and reduce the long-term vulnerability of people experiencing homelessness.