Extant literature has seldom examined the naturalistic role of reaction to threat on downstream emotional distress while also considering buffers, such as perceived social support, to acute negative mental health outcomes. The present study examined how trauma symptoms, in reaction to a global stressor, predicted increased psychological distress via elevated emotional hostility and whether perceived social support modified such effects. We predicted a priori that increased exposure to trauma would be associated with increased hostility and global psychological distress, but that this path would be attenuated by greater levels of perceived social support, as individuals who report greater support exhibit greater emotional coping. We recruited 408 adults from a large university in the Midwestern United States to participate in a survey assessing past-week trauma, hostility, distress, and perceived social support following the initial COVID-19 lockdown. The survey was conducted in March 2020, directly after strict shelter-in-place orders were locally mandated. To test our hypotheses, we employed a moderated mediation analysis approach. Results demonstrate that higher trauma predicted increased hostility, which in turn predicted increased distress, and trauma predicted distress via hostility (an indirect effect). As hypothesized, higher perceived social support attenuated the association between trauma and hostility. Results support a hostile emotional pathway that may increase distress in the context of increased traumatic impact; however, social support likely buffers these effects, particularly in the face of new or novel threats and stressors. Findings suggest broad application for understanding the relation between the introduction of stressors, psychological distress, and social support.