Post-traumatic stress disorder (PTSD) in later life poses a substantial burden on public health and social care systems. However, research in this population remains scarce. In this Personal View, we review the current state of research on PTSD and ageing, as presented by the On Traumatic Stress and Ageing: A Global Network task force, part of the Global Collaboration on Traumatic Stress. Evidence-based knowledge on PTSD in older (aged 60 years or older) trauma survivors was synthesised across four clinical domains: ageing mechanisms, assessment, treatment, and care. 142 publications were reviewed to integrate available evidence and establish consensus-based research priorities. The findings highlight the urgent need for high-quality research across all four domains on older trauma survivors. Future studies should focus on older under-represented groups, such as women; individuals with multiple comorbidities, including neurocognitive disorders; and populations in low-income and middle-income countries. Using standard diagnostic instruments, establishing clinically meaningful functional outcomes, and engagement of people with lived experience should be prioritised to be applied in future research.