"I Think We're Alone Now" is a song written by Ritchie Cordell. It was initially a 1967 hit for American recording artists Tommy James & the Shondells, reaching #4 on the Billboard Hot 100 during a 17-week stay. The recording was produced by Cordell and Bo Gentry.

Rock critic Lester Bangs called the single "the bubblegum apotheosis." Cordell wrote or co-wrote many songs for James, including "Run, Run, Baby, Run" (the B-side to "I Think We're Alone Now"), the follow-up single "Mirage," and 1968's "Mony Mony." I Think Were Alone Nowstands out as one of Tommy James' most successful recordings, and was sampled in a scene in the 1980s slasher film Mother's Day.

"I Think We're Alone Now" has since been covered on numerous occasions. In 1987, a version by Tiffany reached #1 in the US, UK, Canada and New Zealand. Several other cover versions have charted as well, including those by The Rubinoos (#45 US, 1977) and Girls Aloud (#4 UK, 2006).

The song was re-popularized when American singer Tiffany covered the song for her first album Tiffany(1987). Tiffany's version of the song spent two weeks at number-one on the Billboard Hot 100 (and was unusually followed on the top spot by another Tommy James & the Shondells cover, "Mony Mony" by Billy Idol) and three weeks at number-one on the UK Singles Chart. The Tiffany version went quadruple platinum in the US in a thirteen week chart run. The video was shot in a shopping mall which echoed the way her early career had been promoted.

When George Tobin, Tiffany's manager, gave Tiffany the cassette of the original version by Tommy James & the Shondells, Tiffany hated the idea of recording a version of her own for her album mostly because she thought the song wasn't modern or hip enough. It turned out to be her biggest hit once she recorded it.

"I Think We're Alone Now" was not the first single off Tiffany's debut album. The first single was "Danny", but radio started picking up "I Think We're Alone Now", another track on the album. It became a runaway number-one hit and was the eighteenth highest selling single for 1987 and the thirty-second highest selling single in Australia for 1988.

This version is referenced in the alternative group Weezer's song "Heart Songs" on the band's 2008 Red Albumbut in the song it is mentioned that it was sung by Debbie Gibson, another teen idol who was around at the same time as Tiffany. When Rivers Cuomo wrote the song, he had noticed the oversight on his part and that he knew that the song was recorded by Tiffany but he left the part in the song where he mentions Debbie Gibson singing the song.

In 2006, the British all-female pop group Girls Aloud covered "I Think We're Alone Now", produced by Brian Higgins and his production team Xenomania for their greatest hits album The Sound of Girls Aloud. The track was released on 18 December 2006, to contend for the Christmas number one. The song also served as the official theme of the movie It's a Boy Girl Thing, which was released in UK cinemas on 29 December 2006.

Until three days before the greatest hits was manufactured, a cover of Irene Cara's "What A Feeling" was going to be in place of "I Think We're Alone Now". Girls Aloud had called their record label on a Friday afternoon to say they'd rather record "I Think We're Alone Now" — the group recorded the song the following morning and the album was mastered on Monday, three days afterwards.

The album version was drastically reworked for the single release, due to the initial version being hasilty recorded; Higgins said that "Xenomania used the only idea they could think of, which was to make the song sound like 'Something Kinda Ooooh'". The single features an alternative vocal arrangement and an entirely new backing track. The song was also given a big band reworking for the Sound of Girls Aloud Tour.

Girls Aloud's cover of the song was widely slated by music critics. It was called "cheap, obnoxious, totally pointless and destined to be loved only by people too out of their heads on Christmas spirit to know any better."

The single debuted at number 50 on the UK Singles Chart a week prior to its physical release, due to download sales. The single was released in order to compete for the coveted Christmas number one single spot. It eventually peaked at number four, being beaten by Leona Lewis' "A Moment Like This". It spent a further five weeks in the top 75. The song also peaked at number eleven on the Irish Singles Chart and spent six weeks in Ireland's top 50.

The video, directed by Alex Hemming and Nick Collett, features the girls trying to rob an Los Angeles casino. The video is based on films like Ocean's 11and Casino.

Three different endings to the video were shot. The first shows the girls getting caught after opening a box full of money in the casino's safe, the second features Kimberley Walsh removing her clothes in front of casino owners, causing them to faint, and the third features the girls playing with the money. 3 Mobile customers were allowed to vote on their favourite ending from November 8 to November 15, 2006. The latter ending won the vote, despite a version of the video with Kimberley stripping being uploaded to the internet. Since March 2007, all versions of the video have been made available to download on iTunes.

The band performed the song at the following events:

The song has been covered by a number of artists including Annakiya, '70s power pop band The Rubinoos, eurodance artist Playhouse, The Spinto Band, The Turtles, Lene Lovich, Pascal featuring Karen Parry, Annakiya, The Click Five, The Birthday Massacre, Comadre, The Pipettes, Snuff, Screeching Weasel, The Monkees, The Crimea and Me First and the Gimme Gimmes. The song has also been covered by Bel's Boys on their debut album People Let's Go. The latest cover of the song was recently released by The Birthday Massacre on their Looking Glass EP.

The song was spoofed by "Weird Al" Yankovic on his 1988 album, Even Worse, as "I Think I'm a Clone Now". Dave Garr, who wrote a good deal of song parodies about computers, covered this as "I Think We're a Clone Now". The parody dealt with the licensing of the Macintosh from Apple Computer to other companies during the short period in which Macintosh clones were made. The video was recorded in 1995 at Apple's headquarters and features the building and its landmarks of the day, references to former Apple CEOs Mike Spindler and John Sculley, and some vintage Macintosh computers including a Macintosh Classic and an Apple Lisa.

Also, as part of RadioShack's new "TheShack" commercial campaign, one commercial features a man in an office cubicle with headphones on, singing part of the bridge and chorus in a falsetto range.