John Herbert Dillinger Jr. (June 22, 1903 – July 22, 1934) was an American gangster and bank-robber in the Depression-era United States. He was charged with the murder of an East Chicago police officer, but never convicted. During his bank heists, a dozen victims—prison officers, police, federal agents, gangsters and civilians—were killed. His gang robbed two dozen banks and four police stations. Dillinger escaped from jail twice.

In 1933-34, among criminals like Baby Face Nelson, Pretty Boy Floyd, and Bonnie and Clyde, Dillinger was the most notorious of all. Media reports were spiced with exaggerated accounts of his bravado and daring. The public demanded federal action and J. Edgar Hoover developed a more sophisticated Federal Bureau of Investigation as a weapon against organized crime.

After evading police in four states for almost a year, Dillinger was wounded and returned to his father's home to heal. He returned to Chicago in July 1934 and met his end at the hands of police and federal agents who were informed of his whereabouts by Ana Cumpanas. On July 22, the police and Division of Investigation closed in on the Biograph Theater. Federal agents, led by Melvin Purvis, moved to arrest him as he left the theater. He pulled a weapon and attempted to flee but was shot three times and killed.