Monkey Business is the fourth studio album by American group the Black Eyed Peas. It was released on May 25, 2005, by A&M Records, Interscope Records and will.i.am Music Group.

Following the global success of their third studio album Elephunk (2003), the group embarked on the Elephunk Tour. While touring, they began recording Monkey Business in June 2004, continuing for the following six months at various locations worldwide. Executive producers Ron Fair and will.i.am enlisted producers Printz Board, Noize Trip, Timbaland and Danja for the album. Their final product was a hip hop, pop and R&B record incorporating an array of genres, such as crunk, funk, reggae, Raï, calypso, soul, jazz and Latin rock. Similarly to Elephunk, it explores lyrical themes such as relationship complexities, sexual attraction, partying, fame and, to a lesser extent, social issues. Controversy arose over the lyrics of the track "My Humps", which center on a woman using her physical attributes to accomplish her goals.

Monkey Business received mixed reviews from music critics, who complimented its production but criticized its lyrical content and the Black Eyed Peas' inclining to commercialization with the album. It debuted at number two on the US Billboard 200 with first-week sales of 291,000 units, becoming the group's first top-ten album on the chart. The album was certified triple platinum by the Recording Industry Association of America (RIAA), selling over four million copies in the United States. Internationally, it reached number one in Australia, Canada, France, Germany, Mexico, New Zealand and Switzerland, and has sold over nine million copies worldwide. Despite its critical response, the album won two Grammy Awards for its singles "Don't Phunk with My Heart" and "My Humps", receiving three additional nominations.

Monkey Business produced four singles. "Don't Phunk with My Heart" became the group's highest-peaking single on the US Billboard Hot 100 at the time, peaking at number three, and reached number one in Australia, Canada, the Czech Republic, Finland and New Zealand. "Don't Lie" peaked at number 14 on the Billboard Hot 100, being overshadowed by its successor "My Humps", which began receiving heavy unsolicited airplay. After its official release as a single, "My Humps" peaked at number three on the Billboard Hot 100, reaching number one in Australia, Canada, Ireland and New Zealand. The final single "Pump It" became the album's lowest-peaking single on the Billboard Hot 100, reaching number 18. The album was further promoted with two global concert tours–The Monkey Business Tour (2005–2006) and the Black Blue & You Tour (2007).