High school killings in the United States

On April 20, 1999, twelfth-grade students Eric Harris and Dylan Klebold murdered 13 students and 1 teacher in a school shooting and attempted bombing at Columbine High School in Columbine, Colorado, United States. Twenty people were injured by the gunfire, and three others were injured while trying to escape. The attack ended when Harris and Klebold died by suicide. The Columbine massacre was the deadliest mass shooting at a K–12 school in U.S. history until the Sandy Hook Elementary School shooting in December 2012. It remains among the most infamous massacres in the United States and the deadliest mass shooting in Colorado. As of June 2025, it had inspired more than 70 copycat attacks, a phenomenon dubbed the Columbine effect, and Columbine has become a byword for modern school shootings.

2018 mass shooting in Parkland, Florida, USA

mass shooting in Santa Fe, Texas, United States

mass shooting in Barrow County, Georgia

shooting that occurred on November 30, 2021

school shooting in Springfield, Oregon in 1998

a November 14, 2019, school shooting at Saugus High School in Santa Clarita, California

School shooting

2025 school shooting in Antioch, Tennessee

Mass murder in California