Introduction and objective: Both the illness itself and hospitalisation due to COVID-19 are potentially traumatic experiences, especially when the course of the disease is severe. Resilience has been identified as a crucial factor in the process of successfully coping with traumatic events and may protect against the development of symptoms of post-traumatic stress disorder. The aim of this study was to determine the role of resilience in the prevention of post-traumatic stress disorder symptoms in patients requiring hospitalisation due to COVID-19. Materials and methods: A total of 138 patients (59 women, 79 men; mean age: 52.34 years; standard deviation, SD = 12.46) hospitalised at the University Hospital in Krakow were included in the study, which was conducted 7–8 months after their COVID-19 diagnosis. The PTSD Checklist for DSM-5 (PCL-5) and the Resilience Measurement Scale (SPP-25) were administered, and stepwise multiple regression analysis was used in the predictive models. Results: A total of 31 participants (22.5%) met the criteria for probable post-traumatic stress disorder symptoms. The study participants were characterised by a moderate level of resilience (5th sten), with women exhibiting lower levels than men. Higher levels of resilience were associated with lower severity of PTSD symptoms. A significant predictor of post-traumatic stress disorder symptoms was “Tolerance for failure and treating life as a challenge”. Conclusions: Resilience has an impact on the severity of symptoms of post-traumatic stress disorder. Specifically, the dimension of “Tolerance” within resilience appears to be an important protective factor against post-traumatic stress disorder symptoms after hospitalisation for COVID-19. Patients hospitalised with severe course of COVID-19 exhibit a moderate level of resilience, with men demonstrating higher resilience levels than women.