Adverse childhood experiences (ACEs) have historically included child maltreatment, household dysfunction, and other critical issues known to impact children negatively. Although youth experiences with violence are broadly captured in some ACE measures, youth exposure to violence involving a gun has not been included specifically in the operationalizing, and therefore scientific study, of ACEs. There are numerous implications of this omission, including limiting access to ACE interventions that are currently available and resources for individuals who have been exposed to gun violence. Thus, and given the persistent prevalence of gun violence in the US, we conducted a systematic review of the literature over the past two decades on the assessment of and response to ACEs and gun violence. Eighty-one journal articles across four search engines met our inclusion criteria. Our findings provide evidence that youth gun violence exposure should be classified as an ACE. In addition to increasing access to resources for youth affected by gun violence, these findings may improve the likelihood of funding and research into gun violence, with direct implications for prevention and intervention efforts.