Introduction: Firearms are the most frequent means of youth suicide for the 14–18-year-old age group, and adolescent firearm access confers substantial increases in the risk of suicidal behaviors. There have been significant increases in firearm purchases and firearm violence in the United States since the onset of the COVID-19 pandemic. Methods: This study uses four time points of nationally representative data from the Youth Risk Behavior Survey (YRBS) from 2015 to 2021 to examine the differential associations of reporting having carried a firearm and suicide-related outcomes, after controlling for relevant demographic factors. As a sensitivity analysis, we examined whether a similar risk pattern was seen for the probability of reporting depressed mood. Results: Results reveal significant increases in suicide-related outcomes among students who reported carrying a firearm and no significant increases among those who did not. Unlike the suicide-related outcomes, increases in depressed mood overtime were not limited to students who carried firearms, suggesting that the risk associated with firearms may be specific to suicide-related outcomes. Conclusions: Carrying a firearm is associated with significant increases in the risk of suicidal ideation and behaviors among youth and this risk has increased between 2015 and 2021. Implications for youth suicide prevention and directions for future research are discussed.