"Irreplaceable" is a song recorded by American singer-songwriter Beyoncé Knowles. The song was written by Beyoncé, Ne-Yo, Tor Erik Hermansen, Mikkel S. Eriksen, Espen Lind, Amund Bjørklund, and was co-produced by Stargate and Beyoncé for her second solo album, B'Day (2006). "Irreplaceable" was not intended for Beyoncé because the tune was not fitted to her voice and was written from a male's viewpoint. After hearing the demo, Beyoncé made her vocal arrangements and alterations on it. The country-turned-R&B-pop oriented song uses a gently-strummed acoustic guitar. "Irreplaceable" was part of Beyoncé and Ne-Yo's vision of creating a record that people could relate. The lyrics refer to breaking up with an unfaithful man, considered as a female empowerment anthem.

Following the less successful chart performances of "Déjà Vu" and "Ring the Alarm", "Irreplaceable" was released domestically as the album's third single late in 2006, and as the second single on most international markets. "Irreplaceable" was a worldwide commercial and critical success, becoming Beyoncé's second best-selling single in her entire solo career since "Crazy In Love and B'Day ' s most successful release. The single performed well on the U.S. Billboard Hot 100, remaining at the top spot for ten weeks. "Irreplaceable" was one of the most successful single of 2007, certified as multi-platinum and propelling Beyoncé as one of the most successful female artist to date.

"Irreplaceable" was lauded by contemporary critics, citing for its distinct production compared to most tracks of the album. The song won awards, including a nomination at the 2008 Grammy Awards for the Record of the Year. The single's music video features the debut performance of Beyoncé's all-female band Suga Mama, and earned Beyoncé additional awards.