A list of events that occurred on May 18 related to Six Flags.
- 1988 – Daws Butler dies.
- 2001 – Vertical Velocity opens at Six Flags Great America.
- 2002
- The Flying Coaster opens at Six Flags Elitch Gardens.
- Le Vampire opens at La Ronde.
- 2019 – Six Flags SkyScreamer opens at Six Flags Darien Lake.