["Journal of Traumatic Stress, EarlyView. ", "\nAbstract\nCommercial content moderators (CCMs) serve as the hidden first responders of the internet, sifting through flagged user‐generated content to keep online platforms safe. In their work, they have repetitive, frequent exposure to traumatic content, including child sexual abuse material, graphic violence, death, hate rhetoric, and more. Yet, relative to other occupations in which trauma exposure is common, the mental health effects of content moderation have received little study. This is in large part because it is a newer profession that arose with the widespread adoption of social media. In this paper, we describe the work and working conditions typical of CCMs and how these contribute to potential mental health impacts. Global labor inequities are discussed with regard to how outsourcing moderation to low‐ and middle‐income countries with stressful working conditions may exacerbate the risk of posttraumatic stress. Research on the mental health effects of content moderation is synthesized. We propose a research agenda for preventing and mitigating the negative mental health impacts of trauma exposure that CCMs experience. Finally, the paper outlines principles for trauma‐informed, psychologically safe moderation systems and discusses implications for clinicians, employers, and occupational health professionals.\n"]