Objective: Crises such as the COVID-19 pandemic have an impact on the daily lives of families with children, which increases the perceived stress on top of everything else. Studies suggest that single mothers may have been especially vulnerable to stress during this pandemic, which leads this quantitative study to examine how the stress experience of single mothers in the context of the COVID-19 pandemic differs from before COVID-19. Methods: Mann–Whitney U tests were performed on matched data from n = 104 single mothers before and n = 104 single mothers during the COVID-19 pandemic in Germany. Results: Findings indicate that the stress experience of single mothers in Germany differs significantly from the stress experience before the COVID-19 pandemic. Conclusions: Therefore, further research should identify resources and stressors for single mothers’ stress experience as well as interventions and support for single mothers. These interventions and support may also be helpful in coping with crises in general.