Coronavirus disease 19 (COVID-19) has had a strong psychological impact on the Italian population. Italy was heavily affected by the virus before other countries in Europe, experiencing the highest number of deaths. Unknown symptoms in the early stages of the pandemic and the absence of clear transmission links affected people’s wellbeing. Individual personality differences played a key role in perceived psychological wellbeing during the pandemic. The present exploratory study sought to evaluate the impact of COVID-19 on psychological health and identify how psychological wellbeing is influenced by personality traits. A total of 2103 participants (64% female and 36% male) completed an online survey that included the Psychological General Wellbeing Index (PGWBI), the Italian Short Personality Inventory (ITAPI), and a general questionnaire. Descriptive statistics and hierarchical regressions were performed using SPSS 25.0 (IBM Corp., Armonk, NY, USA) (The findings showed poor psychological wellbeing in the Italian population. Young people reported the lowest scores. Vulnerability traits negatively influenced some PGWBI domains, such as the total score (β = −0.62), anxiety (β = −0.55), depression (β = −0.46), positivity and wellbeing (β = −0.51), vitality (β = −0.45), general health (β = −0.12), and self-control (β = −0.52). On the other hand, dynamism traits positively affected vitality (β = 0.12) and positivity and wellbeing (β = 0.14). In other words, personality factors related to vulnerability in particular created risk, whereas dynamism offered protection. The results highlight how COVID-19 helped to trigger anxious and depressive states. People feel helpless and vulnerable when facing new, unexpected conditions caused by the virus. These findings may assist mental healthcare professionals in safeguarding psychological wellbeing during emergencies such as the pandemic.