ICT-enabled or digitalized co-production of public services has become increasingly relevant to emergency response and crisis management. This study provides a literature review on this phenomenon, exploring both large-scale crises and frequent emergencies. We found that research in the domain is scarce and focuses mainly on the phenomenon in terms of digital volunteerism. In large-scale crises, they mostly refer to spontaneous forms of volunteering, and in smaller emergencies, to more organized volunteers that collaborate with a response organization over time. Similarities to digitalized co-production in the public sector generally include financial, administrative, ICT, and demographic factors. Differences include, e.g., aspects of coordination, support, and processing by formal actors. We argue that there are benefits of adding a theoretical co-production perspective to digital volunteerism in emergency response and that our literature review can guide future research on models and (the double) use of volunteers in both kinds of emergencies.