Understanding the presence of post-traumatic stress disorder (PTSD) symptoms in quarantined/isolated individuals is essential for decreasing morbidity and mortality caused by the COVID-19 pandemic. However, there is a paucity of evidence quantifying PTSD status globally during confinement in quarantine/isolation facilities during COVID-19. Therefore, we aimed to assess the PTSD status and factors contributing to PTSD development in quarantined/isolated people during pandemic. Using the Impact of Event Scale-Revised (IES-R) scale, our multicentre, multinational, and cross-sectional online survey assessed the psychological impacts on the quarantine/isolation experience of participants suspected or confirmed to have COVID-19, their PTSD status, and various correlates with developing PTSD. We had 944 (35.33%) valid responses (51.1% from females), mostly from Asian countries (635, 71.4%), and 33.9% were healthcare workers. The number of quarantine days in the PTSD symptoms group (using the IES-R cutoff of 24 for symptomatic or full PTSD) was significantly shorter compared to the non-PTSD group (14 (range 14-40) vs. 14 (14-23.75), = 0.031). Lower rates of PTSD symptoms were observed in participants practicing Buddhist religion than in participants having no religion (OR: 0.30; 95% CI: 0.13-0.68; = 0.005); individuals with vocational training had a higher risk of developing PTSD symptoms (OR: 2.28 (1.04-5.15); = 0.043) compared to university graduates. Individuals forced to be quarantined/isolated had higher odds of developing PTSD symptoms than those voluntarily quarantined/isolated (OR: 2.92 (1.84-4.74); < 0.001). We identified several PTSD correlations among individuals quarantined/isolated during the COVID-19 pandemic, including religious practice, reason for quarantine/isolation, education level, and being a case of the infection. These findings can inform worldwide policies to minimize the adverse effects of such social control measures.