Background <p>Mild traumatic brain injury (mTBI), commonly known as concussion, has historically been regarded as a transient and benign condition. However, recent studies suggest it may increase the risk of long-term psychiatric outcomes, including psychosis. This study aimed to systematically review and meta-analyze the association between mTBI and subsequent risk of psychosis.</p> Methods <p>A comprehensive search of PubMed, PsycINFO, and Google Scholar was conducted through June 2025. Studies were eligible if they included individuals with a history of mTBI, a non-TBI control group, and reported psychosis-related outcomes with estimable risk measures. Random-effects meta-analysis was performed using the metafor package in R. Risk of bias and publication bias were assessed, and meta-regression was conducted to explore moderators such as adjustment status and effect size type.</p> Results <p>Seven studies comprising pediatric and adult populations were included. The pooled risk ratio (RR) for psychosis following mTBI was 1.57 (95% CI: 1.28–1.91, <i>p</i> &lt; 0.001), indicating a statistically significant association. The 95% prediction interval (1.03–2.38) suggests generalizability across future studies. No significant publication bias was detected (Egger’s test <i>p</i> = 0.10). Meta-regression found no difference between adjusted and unadjusted estimates (<i>p</i> = 0.802). Sensitivity analyses confirmed the robustness of the findings.</p> Conclusions <p>mTBI is associated with a moderate but statistically significant increase in the risk of psychosis. Given the prevalence of mTBI in the general population, these findings highlight the need for long-term psychiatric monitoring and preventive strategies, particularly in youth and high-risk individuals.</p>