The Universal Orlando Resort has two theme parks – Universal Studios and Universal's Islands of Adventure. During the months of September, October and a few days in November, Universal Studios closes at 5pm. Once the park is cleared of daytime guests, it reopens as “Halloween Horror Nights.”

Halloween Horror Nights (HHN) is a premiere seasonal event hosted at several Universal parks globally. The most famous iterations occur at Universal Studios Florida (in Orlando) and Universal Studios Hollywood (in California). Both parks transform after dark into a series of "Scare Zones" and elaborate haunted houses based on major horror franchises and original concepts. Additionally, Universal Studios Japan in Osaka and Universal Studios Singapore host their own versions of the event, though their themes often cater to local folklore and popular Asian horror cinema. In 2026, Orlando's HHN remains the largest in terms of scale, often featuring 10 haunted houses and 5 scare zones. It is important to note that HHN is a separately ticketed event; a standard daytime park admission does not grant you access to the nighttime festivities. The event typically runs on select nights from late August through early November.