List of mass shootings in the United States in 2023

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, specifically for the purposes of this article, a total of four or more victims. A total of 754 people were killed and 2,443 other people were injured in 604 shootings.

Definitions

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.

A 2019 study of mass shootings published in the journal Injury Epidemiology recommended developing "a standard definition that considers both fatalities and nonfatalities to most appropriately convey the burden of mass shootings on gun violence." The authors of the study further suggested that "the definition of mass shooting should be four or more people, excluding the shooter, who are shot in a single event regardless of the motive, setting or number of deaths."

Definitions generally exclude consideration of the number of persons targeted with lethal intent, perhaps with degraded accuracy from a greater distance, who escape injury from bullets or bullet spall, regardless of injury sustained while evading live gunfire, or medical complications resulting from those injuries (such as infection, concussion, stroke, or PTSD) further down the road.

Stanford University MSA Data Project: three or more persons shot in one incident, excluding the perpetrator(s), at one location, at roughly the same time.