Showbiz was released in various regions around the world through the band's different regional labels: Naïve in France, Motor in Germany, Russia, Turkey and Ukraine, Maverick in the United States, Play It Again Sam (PIAS) in Benelux, and Avex Trax in Japan. The album was also released earlier by some labels: in France, it was released on 7 September, the Motor edition was sold from 20 September, and the album entered American stores on 28 September. A bonus CD was released in Benelux, which contained the same content as the Random 1-8 extended play, without the hidden remixes of "Sunburn".
Showbiz was recorded between 1998 and 1999. However, the album included some older songs in Muse's repertoire, many of which can date as far back as 1996. Most of the songs on Showbiz had already been written at least by 1997. The songs featured on the album were among the "fifty or so" that Matt Bellamy had written before entering the studio. The band selected the songs which they deemed to be the more conventional and "straight-forward" to make up Showbiz. While the songs contain an eclectic and diverse sound featuring subtle classical, jazz, blues, Latin, and world music influences, they have a distinct and cohesive alternative rock aesthetic. The more experimental material was left out of the album to be included as B-sides in the single releases. A few of those songs were later featured on the compilation album Hullabaloo Soundtrack.
John Leckie, the producer of the album, started attending Muse's concerts in the latter half of 1998. Leckie was based at Sawmills recording studio, where the owner Dennis Smith had given the band free recording time the previous year, from which the Muse EP had resulted in 1998. He built up a relationship with the band during this time, coming to say that he'd "want to work with the band if ever they could afford him". Leckie had not worked with many bands for quite some time prior to doing so with Muse. The recording was finished by 15 May 1999.
Upon its release, the album received positive to mixed reviews from music critics, who saw the young band's potential, but were also quick to dismiss the album as promising yet derivative of other alternative rock bands of the 90s. Several critics drew comparisons to Radiohead, due to the fact that Showbiz was produced by John Leckie, who also worked on the aforementioned band's album The Bends. Neva Chonin of Rolling Stone magazine gave the album 3 out of 5 stars, saying "Showbiz, matches Thom Yorke's penchant for majestic agony — screams and the word self-destruction pepper the title track — but with an edge that's quirkier and decidedly more ragged than their elders". Brent DiCrescenzo of Pitchfork said in his review of the album that "Muse expertly boil down Radiohead into punkish radio nuggets.", but went on to question that "despite this promise, where can they go from here?", which resulted in a rating of 6.7 of a possible 10. In a less favourable review, NME said that "'Showbiz' is not as clever as they think it is ... 'Unintended' and the title track are overwrought, prone to excruciatingly bad pseudo poetry", which ended in a 6 out of 10 score from the publication. On the other hand, a more positive review came from Edna Gundersen of USA Today, who gave the album 3 out of 4 stars, saying that the album "offers smart, seductive rock that's sophisticated but not stuffy, fun but not frilly." and that the songs "get a boost from the handsome voice of Matthew Bellamy, who builds tension by vocally snowballing from a hushed intensity to full-throttle wails."
The album has drawn a noticeably greater appreciation and following since its release however, as of 2009 the album was ranked in the top 20 British albums of the last 20 years by the UK edition of MSN. As well as this, several songs from the album appear to have had lasting appeal among fans, such as the title track, which was one of the band's most requested songs during The Resistance Tour in 2010, when the band staged a fan vote for songs to be played during that tour's stadium leg. The song was not played; however, Unintended and Cave were played several times throughout the tour, with Sunburn being introduced during later performances of the tour. Falling Down was also played during The 2nd Law World Tour in 2012. Once again, songs from Showbiz such as Sunburn, Uno, and Muscle Museum were reintroduced to their concerts in 2015 and 2016.
The sleeve design was criticised by Muse biographer Ben Myers, who wrote that it was "just plain strange. Ill-advised. Tacky, even" and "recalled the sort of artwork that Eighties prog-rock revivalists like Marillion used or, worse still, the doodlings of a sci-fi obsessed A-Level art student" instead of "the work of an exciting, new, distinctly modern band."