"The Chipmunk Song (Christmas Don't Be Late)" is a song written by Ross Bagdasarian, Sr. (a.k.a. David Seville) in 1958. Although it was written and sung by Bagdasarian (in the form of a high-pitched chipmunk voice), the singing credits are given to The Chipmunks, a fictional singing group consisting of three chipmunks by the names of Alvin, Simon, and Theodore. The song won three Grammy Awards in 1958: Best comedy performance, Best children's recording, and Best engineered record (non-classical).

The song was very successful, reaching #1 on the Billboard Hot 100 Pop Singles chart, becoming The Chipmunks' first (and only), as well as David Seville's second and final, #1 single. It has the distinction of being the only Christmas record to reach #1 on the same chart. The single sold 4.5 million copies, according to Ross Bagdasarian, Jr. Ironically, before the song's success, "The Chipmunk Song" was featured on American Bandstand's"Rate-A-Record" segment and received the lowest possible rating of 35 across the board.

Between 1959–1962, the single managed to re-enter the Hot 100, peaking at #41 in 1959, #45 in 1960, and #39 in 1962. (Starting in 1963, Billboard would list re-current Christmas songs on a separate chart.) The song managed to chart on the Hot Digital Songs for the first time in 2005, peaking at #35 on that chart.

"The Chipmunk Song" is the last Christmas song to reach #1 on any US single record chart totaling performance of all available records.

With the release and popularity of the film Alvin and the Chipmunksin December 2007, "The Chipmunk Song" re-entered the Billboard Hot 100 at #70. At the same time, a remixed version of the song that appears on the Chipmunks' 2007 album (and soundtrack to the film) Alvin and the Chipmunks: Original Motion Picture Soundtrack, peaked at #66 and was credited as "The Chipmunk Song (Christmas Don't Be Late) (2007 Version)".

The song has been adapted in The Alvin Showas one of its musical segments. The short depicts Alvin looking through various presents to find a hula hoop, even as he reluctantly sings along with the other Chipmunks. At the end of the song, Seville rewards Simon and Theodore with toy planes and Alvin with his hula hoop. The subsequent argument about singing the song again ends abruptly with their Christmas tree falling over, and Seville and the Chipmunks emerge from the mess to wish the viewers a merry Christmas. One notable thing in this segment is that Theodore's voice is lower and deeper.

The song was featured in A Chipmunk Christmas. A depressed Alvin sings along flatly at first (much like the 1958 original), but then leaves the studio to give away his harmonica to a sick boy. As Seville starts to resume recording the song without Alvin, Alvin returns in the nick of time to sing the song with the others.

The song was featured in the '80s and '90s version of Alvin and the Chipmunks, in the episode "Merry Christmas, Mr. Carroll." In that version, Alvin is taken by Dave (as the Spirit of Christmas Past) to his old house, a cabin lodge where he saw Dave and younger versions of himself, Simon and Theodore. There, it was revealed that Dave wrote the song (called "The Christmas Song" in this episode), because it was inspired by the gifts that the young Chipmunks gave him (which was an eraser, a pencil and a piece of paper).

The song was used for he opening credits of the film, Almost Famous.

The song was featured in the film Alvin and the Chipmunks. There were multiple versions of the song in that film, the original with Ross Bagdasarian, Sr.'s voice, a new one with Jason Lee's voice as David Seville, and a rock mix.

The original recording featured in the film Donnie Brasco(1997).

In the 2009 film Ice Age: Dawn of the Dinosaurs, The song is briefly sung by Crash and Eddie while in a gas which was like helium.

In most subsequent releases since the song's original release, the first verse on the original recording has been re-recorded, sounding more exaggerated than the original release, which contained "Almost Good" as the flip side. There is also a version with the Chipmunks and rock group Canned Heat which was first issued as a single in 1968, which is a bonus track on the 2007 re-release of the Chipmunks' first Christmas album, Christmas with The Chipmunks, this version is the official remix of the original version of the song. On the Solid Gold Chipmunks: 30th Anniversary Editiongreatest hits album (1988), this song appears, but with an altered bridge and ending. Instead of Dave yelling at Alvin for how flat he is in the first verse, Alvin instead appeals that he has asked for the hula-hoop for years but has never gotten it. Dave answers by telling him to finish the song, and they'll discuss it later. After they finish, Dave tells Alvin that something came in for him. It's the hula-hoop that he's been asking for, and the song fades out with Alvin now rattling off a long list of what else he desires for Christmas. The Solid Gold Chipmunksalbum, Here's Looking at Mealbum, and The Chipmunk's 35th Birthday Party(1993) are currently the only known albums that contains this version. There are two versions of the song that both feature Kenny G on the album A Very Merry Chipmunk(1995), that features a more jazz version of the song with Kenny G playing the saxophone during the song, the first is the long version with Alvin complaining about Kenny G and his success as a jazz saxophone player and him helping Alvin to learn to play the sax, the second version called The Chipmunk Song (Christmas Don't Be Late) (Reprise)is the first version but with the talking removed and just the song with Kenny G playing the sax and the Chipmunks singing the song. There was also a version with the Chipmunks and CCM singer, Jaci Velasquez in which Alvin fell in love with Jaci and changed the line "Hula Hoop" into "Date With You".

On the album, "Disney's Merry Christmas Carols," Chip 'n Dale sing "The Chipmunk Song" with Donald Duck in the background.

In 2008 Rosie Thomas released "A Very Rosie Christmas" which featured a slower tempo contemplative rendering of Christmas Don’t Be Late.