Six Flags Fright Fest is a Halloween-oriented haunt event held annually at Six Flags theme parks in the United States, Canada, and Mexico. It mainly features haunted attractions, themed areas named Scare Zones, and live entertainment. The event has always boasted spooky decor and other related live entertainment. Fright Fest officially began in 1988 at Six Flags Over Texas and expanded to several other parks within the Six Flags chain in the seasons to follow. The event has evolved over the years, and in 2020, Fright Fest was reimagined to Hallowfest, due to the COVID-19 pandemic.

During the day, the park offers a family-friendly experience with the Six Flags Kids Boo Fest. Children can trick-or-treat throughout the park, paint pumpkins, participate in a screaming contest, or navigate the hay maze. However, as night falls, The Awakening ritual releases hoards of zombies, ghouls, and other maniacal beasts into the park with one mission: terrifying guests. Specially designated Scare Zones have the highest concentration of terror. Six Flags parks are heavily decorated for Fright Fest, and mainly feature haunted attractions at an extra charge, as well as live entertainment and scare zones. Halloween-based shows are also performed, most notably "Love at First Fright" at Six Flags Great America, Six Flags St. Louis, and Six Flags Great Adventure.

Fright Fest 2023 will be held from September 15 to October 31. Six Flags Over Texas, for example, will feature spooky entertainment, scare zones, and a number of haunted houses and other special park attractions. The park will also have several live entertainment options during Fright Fest, including Aranias Afterlife and The Awakening. Six Flags Fiesta Texas will feature frightful haunted houses, eerie scare zones, and spine-chilling top-notch live entertainment. Six Flags Over Texas has several new haunts and shows for Fright Fest 2023, including "Aranias Murder Mansion" and "The Art of Torture".