|Labels||AFM, Breaker, GUN, RCA|
|Associated acts||Accept, Gotthard, Bullet, Edge of Forever|
|Past members||Peter Szigeti|
Following Udo Dirkschneider's departure from Accept in 1987, he formed his own band called U.D.O. He recruited guitarists Mathias Dieth and Peter Szigeti, bassist Frank Rittel and drummer Thomas Franke. They released their debut album titled Animal House on 3 November 1987, which was entirely written by Accept. They would tour with the likes of Guns N' Roses, Lita Ford and Zodiac Mindwarp. Rubach, Rittel and Franke departed the band, and guitarist Andy Susemihl, bassist Thomas Smuzyszki and drummer Stefan Schwarzmann joined. The follow-up album Mean Machine was released on 10 January 1989.
Susemihl left the band, with U.D.O. now as a four-piece. The band shifted to a lighter approach with the third album Faceless World, which was released on 25 February 1990, achieving great success; this being their best selling album so far. It was produced by former Accept drummer Stefan Kaufmann. The fourth album Timebomb was released on 3 April 1991. It was a more heavier album than their previous releases. In 1992, Dirkschneider put U.D.O. on hiatus to reunite with Accept.
In 1996, Dirkschneider reactivated U.D.O. with a brand new line-up; Stefan Kaufmann, now undertaking guitar duties, with guitarist Jürgen Graf and bassist Fitty Wienhold from Bullet, and Stefan Schwarzmann returning to the band. They took part in the 1997 compilation album A Tribute to Judas Priest: Legends of Metal, in which they recorded the song "Metal Gods".
On 24 March 1997, U.D.O. released the fifth album Solid. It was featured on the Rock Hard magazine reader charts for more than a year after its release. The album was followed up with No Limits on 20 April 1998, featuring a similar songwriting approach from Solid. The album features a cover of the Austrian pop band Supermax's hit single "Love Machine". After the conclusion of the band's tour, Stefan Schwarzmann quit the band. New drummer Lorenzo Milani replaced him.
The seventh album Holy was released on 18 October 1999, which received critical acclaim. It was a return to the guitar-driven sound similar to the Balls to the Wall-era Accept. A world tour followed with dates in the United States and several other major countries. The band known as Vanize, fronted by Udo Dirkschneider's brother Peter, supported U.D.O. during the tour. Line-up changes occurred during the second part of the tour with Gotthard guitarist Igor Gianola replacing Jürgen Graf. The tour spawned the first live album Live from Russia, which was released on 15 October 2001, a 2-CD release featuring many of the classic Accept songs that have since become staples of U.D.O.'s set.
On 24 July 2002, the eighth album Man and Machine was released. It received a somewhat lukewarm reception. Despite standout songs such as the title track and "Private Eye", the album was ultimately less successful than Holy. It is notable for the song "Dancing with an Angel", featuring a duet performance of Dirkschneider and vocalist Doro Pesch.
U.D.O. released their ninth studio album Thunderball on 29 March 2004. The follow-up album Mission No. X was originally due for release on 4 October 2005, but was pushed forward by one week and was released on 30 September 2005 instead. It was the first album to feature Edge of Forever drummer Francesco Jovino.
On 18 May 2007, the eleventh album Mastercutor was released. In August 2007, bassist Fitty Weinhold was unable to perform with the band due to "private reasons". He would be temporarily replaced with former Majesty bassist Marcus Bielenberg for touring purposes.
U.D.O.'s twelfth studio album Dominator was released on 21 August 2009. The next studio album Rev-Raptor was originally due for release on 14 January 2011, but was delayed until 18 March 2011 due to the recurrence of Stefan Kaufmann's back problems. It received another delay, and was finally released on 20 May 2011.
In September 2012, Kaufmann announced his departure for health reasons. He would continue to work in the surroundings of the band and produce for other bands in his own personal studio. On 15 January 2013, Russian guitarist Andrey Smirnov was recruited as the new member. A week later, Igor Gianola left the band "due to conflicts between band appointments and his private life and business." Following his departure, former Amberian Dawn guitarist Kasperi Heikkinen joined the band. The fourteenth album Steelhammer was released on 20 May 2013.
In December 2014, drummer Francesco Jovino left the band for personal reasons, joining Primal Fear in 2015. He was replaced by Udo Dirkschneider's son Sven in February 2015. U.D.O. released the fifteenth studio album Decadent on 23 January 2015.
In February 2017, Heikkinen announced his departure citing personal reasons. According to the band, no bad blood or drama were involved between the two. In March 2017, guitarist Bill Hudson was announced as the new member. On 24 April 2018, Hudson parted ways with the band "due to a difference in their individual visions for the future", according to Dirkschneider, adding that there was no "negative feelings on either side." In June 2018, Stefan Kaufmann temporarily rejoined the band only for the summer festival appearances until a new guitarist was found. The sixteenth album Steelfactory was released on 31 August 2018, with the first single "Rising High" being made available for streaming. On 19 September 2018, bassist Fitty Wienhold announced his departure from U.D.O., but stated that he would remain with the band if needed, " as a friend, as an advisor..." The band soon recruited German guitarist Dee Dammers and renowned Slovenian bassist Tilen Hudrap (Pestilence, Vicious Rumors,Testament(live), Paradox) as their new members.
During U.D.O.'s touring in Europe in early 2019, Dirkschneider performed as a handicap after experiencing left knee pain. He vowed to continue without doctors' advice and without causing disappointment to the fans. The band was originally scheduled to perform at the Wacken Open Air festival in 2020 by performing Accept's 1985 album Metal Heart in its entirety to celebrate its 35th anniversary, with the addition of Das Musikkorps der Bundeswehr, but the festival was cancelled due to the COVID-19 pandemic. In 2020, U.D.O. collaborated with Das Musikkorps der Bundeswehr to record an album titled We Are One, which was released on 17 July 2020. It reached number 8 in the official German album charts, the second highest position for any U.D.O album in 34 years, right after Steelfactory, which peaked at number 7.
A live album titled Live In Bulgaria 2020 – Pandemic Survival Show was released on 19 March 2021. It was recorded live on 18 September 2020 in front of 2500 fans in Plovdiv. The seventeenth studio album Game Over will be released on 22 October 2021.
U.D.O. performed under the name Dirkschneider for an occasion in which Udo Dirkschneider described as his "farewell to Accept", stating that he would no longer perform Accept songs again in the band's live shows. In early 2017, they performed in North America. A 2-CD live album titled Live: Back to the Roots was released on 28 October 2016. An updated version titled Live: Back to the Roots – Accepted! was released on 4 August 2017, featuring a DVD of their performance from Brno, Czech Republic.
The band continued to perform Accept songs for at least another year, due to the request from fans. They returned to North America in early 2018 after a positive reception from their first visit the previous year. In 2018, Udo Dirkschneider put his side project to a close as he did not want to cause confusion between his main band and his side project.
- Animal House (1987)
- Mean Machine (1989)
- Faceless World (1990)
- Timebomb (1991)
- Solid (1997)
- No Limits (1998)
- Holy (1999)
- Man and Machine (2002)
- Thunderball (2004)
- Mission No. X (2005)
- Mastercutor (2007)
- Dominator (2009)
- Rev-Raptor (2011)
- Steelhammer (2013)
- Decadent (2015)
- Steelfactory (2018)
- Game Over (2021)
- Udo Dirkschneider – vocals (1987–1992,1996–present)
- Andrey Smirnov – guitars (2013–present)
- Sven Dirkschneider – drums (2015–present)
- Tilen Hudrap – bass (2018–present)
- Dee Dammers – guitars (2018–present)
- "U.D.O. Confirm Track Listing For "Man And Machine"!". Blabbermouth.net. Retrieved 21 December 2001.
- "Dirkschneider And Pesch Team Up On U.D.O. CD". Blabbermouth.net. Retrieved 10 January 2002.
- "U.D.O.: New Album Details Revealed, Audio Samples Available". Blabbermouth.net. Retrieved 7 June 2005.
- "U.D.O.: 'Mission No. X' Cover Artwork Posted Online". Blabbermouth.net. Retrieved 20 July 2005.
- "U.D.O.: 'Mission No. X' To Arrive One Week Earlier". Blabbermouth.net. Retrieved 24 September 2005.
- "U.D.O.: 'Mastercutor' Bonus Tracks Detailed; 'The Wrong Side Of Midnight' Video Available". Blabbermouth.net. Retrieved 9 May 2007.
- "UDO DIRKSCHNEIDER Discusses New U.D.O. Album 'Mastercutor'". Blabbermouth.net. Retrieved 16 June 2007.
- "U.D.O. Recruits Temporary Bassist". Blabbermouth.net. Retrieved 4 August 2007.
- "U.D.O.: 'Dominator' Artwork Revealed". Blabbermouth.net. Retrieved 6 July 2009.
- "U.D.O.: New Album Delayed". Blabbermouth.net. Retrieved 14 October 2010.
- "U.D.O.: New Album Pushed Back To May". Blabbermouth.net. Retrieved 22 November 2010.
- "U.D.O.: Complete 'Rev-Raptor' Album Details Revealed". Blabbermouth.net. Retrieved 28 March 2011.
- "GUITARIST STEFAN KAUFMANN LEAVES U.D.O.; BAND SEEK REPLACEMENT". Bravewords.com. Retrieved 12 September 2012.
- "U.D.O. Announces New Guitarist". Blabbermouth.net. Retrieved 15 January 2013.
- "Guitarist Igor Gianola Leaves U.D.O., Replacement Announced". metalunderground.com. Retrieved 24 January 2013.
- "U.D.O.: 'Steelhammer' Track Listing Revealed". Blabbermouth.net. Retrieved 8 March 2013.
- "DRUMMER FRANCESCO JOVINO LEAVES U.D.O.; BAND SEEK REPLACEMENT". Bravewords.com. Retrieved 23 December 2014.
- "Primal Fear - Drummer Aquiles Out, Francesco Jovino In". metalstorm.net. Retrieved 14 June 2015.
- "UDO DIRKSCHNEIDER's Son SVEN Joins U.D.O. As Band's Drummer". Blabbermouth.net. Retrieved 6 February 2015.
- "U.D.O.: 'Decadent' Track Listing Revealed". Blabbermouth.net. Retrieved 14 November 2014.
- "Guitarist KASPERI HEIKKINEN Quits U.D.O. And DIRKSCHNEIDER". Blabbermouth.net. Retrieved 17 February 2017.
- "U.D.O. And DIRKSCHNEIDER Joined By Guitarist BILL HUDSON". Blabbermouth.net. Retrieved 31 March 2017.
- "Guitarist BILL HUDSON Exits U.D.O. And DIRKSCHNEIDER After Only A Year". Blabbermouth.net. Retrieved 24 April 2018.
- "Guitarist BILL HUDSON Sets Record Straight Regarding His Exit From DIRKSCHNEIDER". Blabbermouth.net. Retrieved 14 August 2018.
- "UDO DIRKSCHNEIDER Comments On Recent U.D.O. Lineup Changes: 'I Want To Have Fresh Blood In The Band'". Blabbermouth.net. Retrieved 25 August 2018.
- "U.D.O. – The Tank Drives On". Metal Forces.
- "Ex-U.D.O. Guitarist KASPERI HEIKKINEN Fires Back At UDO DIRKSCHNEIDER: His Comments Are 'Bitter' And 'Unprofessional'". Blabbermouth.net. Retrieved 7 September 2018.
- "U.D.O. Rejoined By Guitarist STEFAN KAUFMANN For Summer Festival Appearances". Blabbermouth.net. Retrieved 2 June 2018.
- "U.D.O. To Release 'Steelfactory' Album In August; First Single 'Rising High' Now Available". Blabbermouth.net. Retrieved 15 June 2018.
- "Bassist FITTY WIENHOLD Exits U.D.O. After 22 Years". Blabbermouth.net. Retrieved 19 September 2018.
- "U.D.O. Announces New Guitarist And Bassist". Blabbermouth.net. Retrieved 6 October 2018.
- "UDO DIRKSCHNEIDER Ignores Doctors' Advice, Will Tour With U.D.O. Despite 'Serious Health' Issue". Blabbermouth.net. Retrieved 19 January 2019.
- "UDO DIRKSCHNEIDER To Perform ACCEPT's 'Metal Heart' Album In Its Entirety At Next Year's WACKEN OPEN AIR". Blabbermouth.net. Retrieved 14 September 2019.
- "Coronavirus: Wacken heavy metal festival called off due to outbreak". Deutsche Welle. Retrieved 16 April 2020.
- "Former ACCEPT Members UDO DIRKSCHNEIDER, PETER BALTES And STEFAN KAUFMANN Reunite For U.D.O.'s 'We Are One' Album". Blabbermouth.net. Retrieved 23 April 2020.
- EDITORIAL TEAM. "U.D.O. Announce Release of "Live In Bulgaria 2020 – Pandemic Survival Show"". Sonic Perspectives. Retrieved 13 January 2021.
- "U.D.O. To Release 'Game Over' Album In October". Blabbermouth.net. Retrieved 1 July 2021.
- "UDO DIRKSCHNEIDER To Embark On Special ACCEPT 'Farewell' Tour In 2016". Blabbermouth.net. Retrieved 1 August 2015.
- "UDO DIRKSCHNEIDER Explains Decision To 'Close The ACCEPT Chapter'". Blabbermouth.net. Retrieved 8 October 2015.
- "UDO DIRKSCHNEIDER Announces North American 'Back To The Roots - Farewell To ACCEPT' Tour". Blabbermouth.net. Retrieved 1 June 2016.
- "DIRKSCHNEIDER To Release 'Live - Back To The Roots' Album In October". Blabbermouth.net. Retrieved 18 August 2016.
- "DIRKSCHNEIDER To Release 'Live - Back To The Roots - Accepted!' In August". Blabbermouth.net. Retrieved 13 June 2017.
- "UDO DIRKSCHNEIDER To Continue Performing ACCEPT Classics For At Least Another Year". Blabbermouth.net. Retrieved 21 March 2017.
- "DIRKSCHNEIDER To Return To North America In Early 2018". Blabbermouth.net. Retrieved 9 June 2017.
- "Former ACCEPT Frontman UDO DIRKSCHNEIDER Doesn't Want To Confuse People By Continuing Namesake 'DIRKSCHNEIDER' Band". Blabbermouth.net. Retrieved 18 November 2017.