Both vaccinated and unvaccinated guests will have to wear masks in indoor spaces and throughout all attractions.
The change matches a new recommendation from Orange County, Florida as it phases out COVID-19 restrictions.
Since September, SeaWorld Orlando has passed four surprise county inspections on enforcing local COVID-19 orders.
Each Disney World theme park has now passed at least two COVID-19 inspections from Orange County "strike teams."
The most recent inspection came after Universal saw large crowds over the holidays.
The unannounced visits determine whether theme parks are complying with Orange County, Florida's rules on face masks and physical distancing.