Cinderella is one of the most recognizable Disney princesses, and as such is one of the easiest ones to find within the Disney Parks.
She can easily be found at both Disney Resorts in the US in multiple locations.
In the Magic Kingdom, she can be found in the Princess meet and greet location in Fantasyland as well as a guaranteed character as part of Cinderella's Royal Table.
In Disneyland, she is often found as part of the Fantasy Faire character meet and greet as well, and can often show up unannounced at the entrance of the park, or in the lobby of Great Moments of Mr. Lincoln during the rain.
In Epcot Cinderella can sometimes be found at the Norway Princess meal.
Cinderella used to also be found in Disney California Adventure as part of the Ariel's Grotto character meal, but she left the park along with Paradise Pier.