A list of events that occurred on April 1 related to Six Flags.

• 1976 – Troy Baker is born.
• 1998 – Time Warner sells Six Flags to Premier Parks for $1.86 billion.
• 2005 – Six Flags New England opens for the 2005 season.
• 2006 – Goliath opens at Six Flags Over Georgia.
• 2017 - Patriot at California’s Great America opens.
• 2021
  • Six Flags Magic Mountain opens for the 2021 season.
  • Six Flags Discovery Kingdom opens for the 2021 season.