It’s always felt much more Fantasy to me. It takes place in a world far superior to ours technologically, but it’s still magic, wizards, and a princess. It’s more Tolkien than Asimov.
Science fiction, to me anyway, is where the science and technology play a major part of the story as opposed to just being the setting: 2001: A Space Odyssey, Planet of the Apes, Lost In Space, Battlestar Galactica, Star Trek.
As there have been three versions of POTA, three LIS incarnations, and two BSG’s, you’re going to have to be a little more specific. 😉