Sally is Jack Skellington's love interest. She is a very pretty, loving, caring, and shy rag doll who told Jack that Christmas and Halloween shouldn't be mixed. She is originally patched together by Doctor Finkelstein. Sally is the only one to have doubts about Jack's Christmas plan. Although her creator attempts to keep her constantly imprisoned, she often manages escape by slipping him deadly nightshade, causing him to fall asleep. Nightshade is a flower that grows atop the grave of a dead witch, as seen before Jack's first song which induces temporary somnolence upon consumption. This becomes essential to Sally managing to trick the Doctor and escape. Despite her makeshift appearance, Sally is a determined individual with a good feel for what is right. Fiona Apple provides the vocals for "Sally's Song" on the 2006 special edition of The Nightmare Before Christmas: Original Motion Picture Soundtrack, while Amy Lee provides the vocals for "Sally's Song" on Nightmare Revisited. She also appears in Tim Burton's The Nightmare Before Christmas: Oogie's Revenge.
Sally is a rag doll-type character, with detachable limbs stuffed with fall leaves. She often falls apart, requiring her to sew herself back together, and carries a set of sewing needles and thread for precisely that purpose. She was created by Doctor Finklestein, Halloween Town's resident mad scientist, as a companion. Their relationship is rather tense, as Finklestein insists on keeping Sally under lock and key, under the pretext of protecting her from the excitement of the outside world. However Sally is restless, and is intrigued by the wonders of the outside world.
It is this restlessness, or, more specifically, this desire for something better in her life, that draws her to Jack Skellington. In the beginning of the movie, she idolizes and admires Jack much like any of the other female members of Halloween Town; however, she quickly discovers that they are connected by the desire for something more in their lives, and her feelings for him intensify. The two refer to each other as "friends", though Jack seems unaware of Sally's true feelings for him, as she is too shy to make them known to him other than through her sweet actions, however this could be argued because after Boogie's defeat, Jack and Sally are left alone and Jack sees that Sally tried her best to help him. Thus prompting him to finally realize how much she cares for him and how much he loves her in return.
On the album to the film it is mentioned that years later Sandy Claws returned to Halloween Town and saw that Jack now had four or five skeleton children of his own. Many fans of the film and of the franchise assume that given the ending to the film, that Jack and Sally eventually got married and had a family of their own.
Bryan Theiss declares that "Sally is one of those rare fantasy characters we can relate to on a certain level as much as we can to real-world characters on a more literal level."