"This Is Halloween" is a song from the 1993 film The Nightmare Before Christmas composed and written by Danny Elfman. In the film, it is performed by the residents of the fictional "Halloween Town", which is the film's main setting, and introduces the town's Halloween-centered lifestyle. The song was also included on the film's soundtrack.

"This Is Halloween" was created by Danny Elfman, the main composer for The Nightmare Before Christmas. In the film, it serves as the opening song as the characters of the film introduce themselves and the setting of the film is established.

"This Is Halloween" was covered by the bands Marilyn Manson and Panic! at the Disco in 2006 for the special edition release of the film's soundtrack and subsequently included on the 2008 cover album, Nightmare Revisited.

On the 2011 album V-Rock Disney, which features visual kei artists covering Disney songs, Sadie covered this song. Leetspeak Monsters, a Halloween-themed visual kei band, also covered the song in 2018.

The Swiss/German symphonic metal band Ad Infinitum did a cover in 2020.

The song was performed as part of a virtual Broadway benefit concert hosted by the Disney Music Group on Halloween 2020. Money from the concert was donated to the Lymphoma Research Foundation and the Actors Fund.

In October 2023, the song was added to the soundtrack of the video game Rocket League as part of a Halloween event.

"This Is Halloween" is performed by an orchestra, consisting of a piano, a string section, woodwind and brass instruments, cowbells, tambourines, a xylophone, and a banjo. The residents of the film's fictional Halloween Town sing the vocal parts. Discussing the song, PopMatters contributors noted various "vocal inflections and character impressions", which make the song "spooky yet magically appropriate". Writer David Ventura highlighted the fact that despite multiple artists often singing simultaneously, their voice lines don't overlap, as they're always at least two octaves apart.