The reunited boyband were confirmed to have been chosen by the BBC in a statement made on the corporation's official Eurovision Twitter page. They will perform a new self-penned song entitled 'I Can', with the track's promotion and recording also being filmed as part of a BBC documentary to be screened in April.
BBC Head of Entertainment and Events Katie Taylor commented: "We're enormously pleased to have found an act that not only meets but exceeds all the criteria for a great entry. Blue are the perfect choice and we're so proud to have them representing us at this year's Eurovision Song Contest."
Band member Duncan James also revealed his excitement on Twitter, saying: "Yes the rumour r true!! We r representing the uk in this yrs EUROVISION! We r really excited and cant wait till u hear the song!! ITS BIG!!! (sic)."
The group have previous links to the contest, as Antony Costa came second in the 2006 edition of Eurovision song selection show Making Your Mind Up with 'It's A Beautiful Thing'. Duncan James was also part of the judging panel on the show's successor Eurovision: Your Country Needs You in 2009.
Blue originally formed in 2001 and had a string of top ten hits in the UK, including 'All Rise', 'One Love' and 'Sorry Seems To Be The Hardest Word', a duet with Elton John, before splitting in 2005.
The final of the 2011 Eurovision Song Contest will take place on May 14.