The psychological health and work challenges of nurses working in prisons during the COVID-19 pandemic are understudied. We evaluated the work and wellbeing characteristics of a California prison nurse group, with a comparison to those of a community nurse group. From May to November 2020, an online survey measured psychosocial and organizational work factors, sleep habits, psychological characteristics, COVID-19 impacts, and pre-pandemic recall among 62 prison nurses and 47 community nurses. Prison nurses had significantly longer work hours (54.73 ± 14.52, p < 0.0001), higher pandemic-related work demands, and less sleep hours (5.36 ± 1.30, p < 0.0001) than community nurses. Community nurses had significantly higher pandemic-related fear levels (work infection: p = 0.0115, general: p = 0.0025) and lower perceived personal protective equipment (PPE) supply (p = 0.0103). Between pre-pandemic and pandemic periods, both groups had significantly increased night shift assignments and decreased sleep hours, but the prison group had increased work hours. Although not statistically significant, both groups had high occupational stress and prevalence of post-traumatic stress symptoms. Our results indicate that prison nurses experienced work and wellbeing challenges during the pandemic. Future research and practice ought to address nurses' workload, PPE, and psychological resources in correctional facilities and healthcare organizations.