Morissette was inspired to write the song after watching a rough cut of the film; according to her, the song seemed to flow from her and "really touches me deeply". She wrote it on a Friday, recorded it on Saturday, and handed it in on Sunday. After the release of "Wunderkind", Morissette enlisted producer Mike Elizondo to co-produce her tenth album. The protagonist of the song, which is written from the point of view of the character of Lucy Pevensie, describes herself as "a magnet for all kinds of deeper wonderment", "a wunderkind" and "a princess on the way to [her] throne" during the chorus. The string arrangements were in charge of Harry Gregson-Williams, the movie's composer.
IGN Music wrote that it was "equally captivating" as Imogen Heap's soundtrack contribution "Can't Take It In", with Morissette "letting her warble drip delicately over a piano driven lament. It's one of the best things she's done in a long time."Sci Fi Weekly also described it as "captivating", writing "Morissette delivers [it] with a depth of feeling that makes one sit up and take notice." Movie Music UK called the song "wholly unremarkable ... it doesn't help that Alanis Morissette can't pronounce the word 'wunderkind' properly - it comes out as "wander" (as in walk around aimlessly) and "kind" (as in being nice to someone)." Similarly, Christian Clemmensen of Filmtracks.com wrote "wait until you hear Alanis Morissette belt out her classless pronunciation of '[w]underkind'", and compared it to Annie Lennox's "Into the West", a song on the soundtrack for the 2003 film The Lord of the Rings: The Return of the King.
"Wunderkind" was nominated for the 2006 Golden Globe for "Best Original Song" (see 63rd Golden Globe Awards nominees). After the nominations were announced, Morissette's home was inundated with phone calls, leading her to assume that "something must be wrong, somebody must be hurt"; she later said she was "excited that some light is being shone on [the song]."