Background/Objectives: The previous literature has identified increased work-related stress among healthcare workers (HCWs) during the COVID-19 pandemic. This study analyzes work-related perceived stress experienced by therapists during the COVID-19 pandemic in Germany to identify potential for supporting this crucial group of HCWs in future health crises. Methods: Survey data on stress, measured through the Perceived Stress Scale 4, among HCWs (therapists n = 612, nurses n = 501, and doctors n = 461) were analyzed using descriptive statistics, and data from four semi-structured interviews and seven focus group discussions with therapists were analyzed using thematic content analysis. Data were collected from March to September 2022. Results: Therapists reported similar stress levels to other HCWs, with the reporting of perceived stress differing between work contexts. Eight stressors were identified through the thematic analysis: (1) concerns about maintaining the quality of care, (2) uncertainty about the future, (3) workload, (4) interactions with colleagues and patients, (5) PPE, (6) the risk of infection, (7) insufficient information flow, and (8) the lack of public and political recognition. Conclusions: This study emphasizes the distinct challenges that therapists experienced during the COVID-19 pandemic. By identifying the factors that contributed to the stress experienced, the study can inform targeted support strategies which can enhance therapists’ work, ultimately contributing to sustaining essential healthcare services during public health crises.