A list of events that occurred on May 11 related to Six Flags.

• 1984 – Eight teenage visitors are trapped and killed when the Haunted Castle attraction at Six Flags Great Adventure is destroyed by a fire. The park and Six Flags were subsequently indicted for manslaughter, accused of recklessly causing the deaths by taking inadequate precautions against a fire. In the subsequent trial, the prosecution argued that repeated warnings by safety consultants to install sprinklers or smoke alarms had been ignored.  The defendants denied any culpability, and contended that the fire was arson and that no precautions would have saved lives. The trial jury found the defendants not guilty.
• 1992 – Curtis D. Summers dies.
• 2019 – Opening day of the 2019 season at Great Escape.