Many health and social care (HSC) professionals have faced overwhelming pressures throughout the COVID-19 pandemic. As the current situation is constantly changing, and some restrictions across the UK countries such as social distancing and mask wearing in this period (May–July 2021) began to ease, it is important to examine how this workforce has been affected and how employers can help rebuild their services. The aim of this study was to compare cross-sectional data collected from the HSC workforce in the UK at three time points during the COVID-19 pandemic: Phase 1 (May–July 2020), Phase 2 (November 2020–January 2021) and Phase 3 (May–July 2021). Respondents surveyed across the UK (England, Wales, Scotland, Northern Ireland) consisted of nurses, midwives, allied health professionals, social care workers and social workers. Wellbeing and work-related quality of life significantly declined from Phase 1 to 3 (p < 0.001); however, no significant difference occurred between Phases 2 and 3 (p > 0.05). Respondents increasingly used negative coping strategies between Phase 1 (May–July 2020) and Phase 3 (May–July 2021), suggesting that the HSC workforce has been negatively impacted by the pandemic. These results have the potential to inform HSC employers’ policies, practices, and interventions as the workforce continues to respond to the COVID-19 virus and its legacy.