This is a list of mass shootings that took place in the United States in 2023. Mass shootings are incidents in which several people are victims of firearm-related violence. Several different inclusion criteria are used; there is no generally-accepted definition. Gun Violence Archive, a nonprofit research group that tracks shootings and their characteristics in the United States, defines a mass shooting as an incident in which four or more people, excluding the perpetrator(s), are shot in one location at roughly the same time.The Congressional Research Service provides a definition of four or more killed. The Washington Post and Mother Jones use similar definitions, with the latter acknowledging that their definition "is a conservative measure of the problem", as many shootings with fewer fatalities occur. The crowdsourced Mass Shooting Tracker project applies the most expansive definition: four or more shot in any incident, including the perpetrator....