Given the severity of risks that accompany the current COVID-19 pandemic, many are experiencing negative psychological effects, such as increased symptoms of depression and anxiety (i.e., mental health distress). As the COVID-19 pandemic continues to impress upon society, it is pertinent to assess the ways in which COVID-19 may be impacting first responders; many of which who are responsible for tending to the safety and wellbeing of communities during this time. However, little is known about how medical first responders may be experiencing COVID-19 related stress, whether this impacts their experience with symptoms of mental health distress, and furthermore whether this stress is different for those in different countries. As such, the present study sought to assess the association between COVID-19 related stress and symptoms of mental health distress in medical first responders for those living in Australia and the United States. Further, given the positive effects romantic relationships have on an individual’s interpersonal functioning, the potential moderating effect of perceived relationship commitment was examined. A total number of 79 participants completed the study. Contrary to hypotheses, results showed that there was no significant association between COVID-19 related stress and symptoms of distress, nor was relationship commitment found to moderate symptoms of distress. Implications of this study have the potential to guide mental health professionals working with medical first responders who are experiencing symptoms of distress, particularly in times of crises similar to that of COVID-19.