In your case, a long skirt, that is not part of a costume and does not actually reach or drag on the ground should be fine. You may want to keep the skirt no longer than shin length, otherwise you may find it difficult to enter and exit the various cars and boats used on the attractions.

Yes, you can wear a maxi dress to Disney World, but there is a very important safety rule you must follow: the dress must not drag on the ground. Disney's official attire policy prohibits any clothing that touches or drags on the floor, as this poses a significant trip hazard on escalators, moving walkways, and ride vehicle boarding platforms. If your maxi dress is "floor-length" or has a train, Cast Members at the park entrance may deny you entry or ask you to pin it up. Beyond the rules, practicality is key. While maxi dresses are breathable and offer sun protection for your legs, they can be cumbersome when boarding ride vehicles like Space Mountain or Pirates of the Caribbean, where you often have to step over high ledges or sit in cramped spaces. Many veteran "Disney-goers" suggest choosing a midi-length dress or a maxi with a high-low hem to ensure you don't trip while navigating the crowds or getting caught in the rain, which is a near-daily occurrence in Orlando.