Irritant were a progressive rock / heavy metal band from Gloucester, England, UK, formed in 2002. They originally described themselves as an "independent hard rock band", and flirted with rap, but developed a blend of progressive metal and hard rock. They cited among their influences Black Sabbath, Pink Floyd, Iron Maiden, Rush, Avenged Sevenfold, Guns 'n' Roses, AFI, 80s metal and late 60s progressive rock.
Their 2007 single "Voice of the Siren", described by the BBC as a "gargantuan rock classic", was produced by Vic Coppersmith-Heaven (who previously worked with Black Sabbath, The Jam, and The Rolling Stones) and reached No. 70 on the UK Singles Chart. They band split on 8 February 2008.