I have some info on some celebrities that have been in both Star Wars and Disney Movies
James Earl Jones, the infamous voice of Darth Vader, did the voice of Mufasa in the Lion King, Which when you think about it is kinda funny. I could just picture Mufasa saying "No Simba, I am your Father!" lol
Keira Knightley a.k.a Elizabeth Swan from the Pirates of the Caribbean Trilogy was actually in Star Wars: Episode I: The Phantom Menace before she even knew how to swashbuckle. She played Sabe, Queen Amidala's loyal body guard. Most of the scenes where we see the Queen in beautiful gowns and white make up, which we usually consider Queen Amidala being, isnít Natalie Portman at all but was Keira Knightley. I'm not exactly sure how Will Turner is going to take that Elizabeth was once a queen's body guard.
Warwick Davis who plays the adorable Ewok, Wicket W. Wacket in Episode VI: Return of the Jedi and a plethora of different characters in Star Wars: Episode I (and each character he played names started with a W) is going to pop up in Chronicles of Narnia: Prince Caspian here this coming summer as a dwarf of some kind. Talk about typecasting huh?
The Famed Puppeteer, Frank Oz, the head of the Muppet Company and the voice of several of the Muppet Characters, did the voice of the wise green Jedi Master Yoda in Star Wars I, II, III, V, and VI. There are actually three interesting story to go along with the appearance of Frank Oz in V, VI, and I. After the Success of Star Wars IV, George Lucas decided to make Star Wars Episode V: The Empire Strikes back. The Alien characters of the first movie captivated audiences, so George decided that he needed to make new and different kinds for the sequel. Mr. Lucas found himself being stuck with only being able to do aliens costumes that people could be in and that simply wouldn't work for his new Jedi character Yoda, who was written in the original script as being very small and very wise. So GL started searching for a person who could make some puppets for this character and other small creatures that needed to be in the movie. After a small amount of time, "the maker" sought out the best know puppeteer in the world, Frank Oz. Frank Oz agreed to help him with the puppets and even do the voice of the infamous Yoda. Yoda was an instant hit when Episode V released and, of course, George signed on Frank Oz to do the character again in Episode VI: Return of the Jedi. Frank Oz came back after that long gap in time between VI and I and reprieved his role as Yoda in Episode I. He made a new puppet to make Yoda look younger than the original. Since there were so many new live Jedi characters, the puppet just didn't seem to fit in as well as it used to. So in Episode II: Attack of the Clones the puppet was replaced with a CG character, but Frank still did the voice. Don't worry about the other Muppets though. I seriously doubt that Kermit and Miss Piggy are going to be replaced by a CG Frog and Pig. And think of it this way, how lame would that fight scene between Yoda and Count Dooku be if Yoda was a Puppet on a pole doing those flips? lol "Frank Oz not only was the voice and puppeteer behind Yoda, but he also provided the voice for Fungus (Randall's scare assistant in Monsters Inc.). Mr. Oz was also involved with the films Labyrinth (puppetry), Dark Crystal (co-director with Jim Henson), Little Shop of Horrors (puppeteer), and a variety of films in which he acted." (Last info Courtesy TinkRocks)
The voice of Aslan on the Chronicles of Narnia movies is the same person who played Qui-Gon Jin in Star Wars: Episode 1, Liam Nesson.
I learned something New Jay Laga'aia, who played Senator Amidala's body guard, Captain Typho, in Episodes II and III, was actually on Broadway and played Mufasa in the Lion King show there.
While you may not recognize his face you have probably heard his voice. James Arnold Taylor is the voice of Obi-Wan Kenobi in both the hand drawn and and CG Clone Wars, as well as the video games in that time. He also did the voice of Milo in the Disney Movie "Atlantis" and it's sequel, as well as doing voices for Kim Possible, American Dragon Jake Long, and Pirates of the Carribbean: The Legend of Jack Sparrow. Finally he did the voice of Capn. Jack and Timon in Kingdom Hearts II.
If any of you know of any more, Let me know