Dr. Finkelstein is Sally's creator and a reformed antagonist of The Nightmare Before Christmas.
In the original film, he was voiced by the late William Hickey. In the rest of the franchise, he is voiced by Jess Harnell.
Finkelstein is a smart mad scientist, and he likes to make creations like a wife for himself. He is antagonistic to Sally because he tried to keep her under his spell but, then it backfired. Finkelstein has a new sidekick named Igor and fed him dog treats like a dog.
Doctor Finkelstein lives in a large observatory with his living rag doll creation Sally and his hunchbacked assistant Igor. James Whale's Frankenstein is quoted in Finkelstein's line "I made you with my own hands" which is ironic as Finklestein's body appears to be largely if not entirely artificial. Unlike Frankenstein who takes no responsibility for his creations and disowns them almost as soon as they are completed (much like the original Dr. Frankenstein), Finklestein takes full responsibility over Sally and acts as an over-protective father and in some ways an overbearing husband (thus explaining Sally's attempts to run away) by keeping her under lock and key under the pretext of sheltering her from the world. In addition to being an overbearing and antagonistic father figure for Sally to overcome, Finklestein also has a hand in helping Jack Skellington (of whom he seems to be very fond) with his plan to take over Christmas by bringing to life several skeletal reindeer to pull Jack's sleigh. Near end of the film, Finkelstein, deciding that Sally is too much of a handful, creates a wife for himself using a portion of his own brain, which he finishes at the end of the movie.
- Dr. Finkelstein's overbearing behavior had him appear as the main antagonist, but he was not a true villain. The true main antagonist was Oogie Boogie. However, Finklestein was originally planned to be Oogie Boogie in disguise attempting to get back at Jack and Sally in earlier drafts, but Tim Burton hated the idea (and allegedly kicked a hole in the wall when he heard about it), so this idea was scrapped.