U.D.O. is a heavy metal band from Germany that was founded in 1987. It is the successor band to the former Accept singer Udo Dirkschneider. The first U.D.O. album Animal House was released in 1987, and its successor Mean Machine made it into the Top 40 of the German album charts in 1989 at number 31. The third studio album Faceless World also entered the German charts at number 52 in 1990. One year later, U.D.O. released U.D.O. Timebomb. U.D.O. then announced their dissolution - the reason: singer Udo Dirkschneider took over Accept's microphone again. The renewed collaboration only lasted until 1996, when Udo Dirkschneider returned to his band U.D.O.. The first musical sign of life was the album Solid in 1997, after which things went steadily uphill for the band. The 1998 album No Limits reaches number 90 in the German charts. The musical development progressed and U.D.O.'s fan base grew. In 2009, the band made it into the top 30 in Germany for the first time with Dominator at number 27. Six years later, Decadent made it to number 16. With its direct successor Steelfactory, U.D.O. made it into the German top 10 for the first time at number 7. The album also landed in the top 30 in Austria and Switzerland. In 2020, We Are One (number 8) followed, an album together with the Bundeswehr music corps. in 2023, U.D.O. released the album Touchdown, which reached number 4 in the German charts.