Ninety-eight people, all male, were executed in the United States in 1999 in twenty states, 94 by lethal injection, 3 by electrocution, and one by gas chamber. The most recent execution by gas chamber occurred this year. With ninety-eight executions carried out, 1999 remains the year with the highest number of executions in a single year in the United States since the resumption of executions in 1976. Conversely, Illinois conducted its final execution in 1999 before the state abolished the death penalty in 2011. On December 9, 1999, four executions were carried out in the United States on the same day, the highest number of executions in a single day since the 1950s. This has occurred only once in the modern era.
Ohio carried out its first execution since 1963, that of Wilford Berry Jr., who waived his appeals.
The state of Oklahoma executed Sean Sellers, who became the only juvenile to face the death penalty in the United States for a crime committed under the age of 17 prior to Roper v. Simmons, which banned capital punishment nationwide for anyone under the age of eighteen. Sellers was the first executed for a crime committed at the age of 16 since Leonard Shockley in 1959.