As lead singer with the world renowned group UB40, Ali Campbell has one of the UK’s most distinctive and recognisable voices.

Lead singer with the world-famous group UB40, which has sold over 70 million records worldwide, Campbell has toured across the globe and notched up four number No. 1 world-wide singles with the group, including over 40 Top 40 UK singles, released 18 studio albums and received an Ivor Novello Award for International Achievement. At the 2007 Grammy awards UB40 were nominated for best reggae album, for their most recent album released in 2006.

On 24 January 2008, it was reported that Campbell was to quit the group after almost 30 years. Campbell, who sang on hits such as Red, Red Wine, intended to concentrate on his solo work, the band said in a statement. The Birmingham reggae band's last gigs together were in February 2008 in Australia, New Zealand and Uganda. A spokesman for the band said they would continue to record and perform with the existing seven members. UB40 is currently touring the U.S. with other brother Duncan Campbell as a replacement for Ali, along with Marvin Priest (son of Maxi Priest) as a fill in for Astro, who is continually barred from entry into the U.S. due to visa problems. Maxi Priest is also currently performing with UB40 as a special guest, lead singing on certain UB40 and Bob Marley classics during the band's performances.

On 25 January 2008, Campbell said that he was leaving after almost 30 years because management difficulties had become "intolerable". He claimed the disagreements had been going on for nearly five years and he was "deeply unhappy" with many decisions. A UB40 spokesman disputed his comments over the situation with management.