"Irreplaceable" is a song written by American singer-songwriters Ne-Yo and Beyonce, and Norwegian songwriters Mikkel S. Eriksen, Tor Erik Hermansen, Espen Lind, and Amund Bjørklund for Knowles' second studio album B’Day. Produced by Norwegian production team Stargate and Beyoncé, the song was released as the album's third single domestically, and the second single outside North America in October 2006. "Irreplaceable" reached number one on the Billboard Hot 100 on December 16, 2006, making it Beyoncé's eighth Billboard number-one, and her fourth as a solo artist (her first without a guest rapper). It has sold over two million copies in digital sales. It was the last U.S. #1 of 2006 and the first of 2007. The song was released as a single on October 23, 2006 and was recorded in Sony Music Studios in New York City. "Irreplaceable" was the Billboard Hot 100 number-one single for ten weeks, and has received world wide critical acclaim. In the United States, it has become the most successful song of her solo career. In December of 2006, a Spanish-language version of "Irreplaceable" entitled "Irreemplazable" (which means "Irreplaceable") was released. This remix has peaked on #4 on Billboard's Hot Latin Songs. It has also been faring fairly well on charts in Latin countries and was included in her Spanish language re-release of B'Day. In the UK the song was used, along with Beyonce, in TV commercials for the Samsung Ultra Music SGH-F300 cell-phone. The song will be featured on her newest CD Irreemplazable.


What started this song was a musical idea. Stargate Produced the track, using acoustic guitar parts made by Espen Lind and Amund Bjørklund, and then making it into a full track with drums, bass and strings. This beat was presented to Ne-Yo who loved the idea, and wrote lyrics and melody (along with Knowles) on the spot. The song was then played to Beyonce´ and she recorded the song for her B´Day album.
According to Beyoncé, "Irreplaceable" is meant to empower her female fans by encouraging them to end bad relationships: "Irreplaceable is a secret weapon...It's a celebration of a breakup and makes women feel like they're worth more." The song is about putting out her boyfriend after he cheats and says that he was foolish to think that she won't find someone if he leaves.

The song was well-received by critics. While many of the tracks from B’Day have been upbeat club-bangers, featuring heavy 808-driven beats, "Irreplaceable" has been praised by critics for its simple, guitar-driven melody. Bill Lamb of About.com gave the song four and a half stars, and characterized it as "one of the strongest" tracks from the album. He praised Stargate for the "simple, pop-oriented production" and the "subject matter of female strength and independence." Lamb ranked "Irreplaceable" the fourth best R&B song of 2006. Barry Schwartz of Stylus Magazine wrote that "Irreplaceable recaptured "Crazy in Love"’s near-perfection....(and features) her most genuinely emotional vocal to date, equal parts vulnerable, upset, vindictive, resigned, and apathetic."

For Entertainment Weekly, Jody Rosen said the track was "a lilting tune unlike anything Beyoncé has ever performed," while Billboard magazine praised "Irreplaceable"'s simplicity and 'radio-friendliness,' noting that the "song dilutes the excessive instrumentation of B's first two singles in favor of smooth drum taps and guitar strumming" and "should blast off at radio." In their review of B'Day, the popular indie-oriented website Pitchfork Media declared "Irreplaceable" the album's best song, calling it "(Beyoncé's) most sophisticated and her most honest performance to date". Irreplaceable won the Soul Train Music Award for "Best R&B/Hip-Hop Single, Female," and the Nickelodeon Kid's Choice Award for "Favorite Song". Beyonce also won Video of the Year at the 2007 BET Awards for Irreplaceable and also won Best Female R&B Artist of the Year.