Matt Walker began his career in Chicago in the mid-1980s, when he began playing drums for the Chicago bands Scott Bennett & The Obvious, The Clinic, Brad Peterson and Peat Moss and Tribal Opera until joining the band Filter in 1994. Matt toured with Filter in support of the album, "Short Bus" until 1996. Filter toured with The Smashing Pumpkins in Europe and when Pumpkins drummer Jimmy Chamberlin was fired after a heroin overdose, Walker was hired to replace Chamberlin. He finished the Mellon Collie and the Infinite Sadness tour with the band (1996 - 1997) and all of their dates up until the beginning of the Adore tour. Walker also recorded the song "The End Is the Beginning Is the End" with the band on the official Batman & Robin movie soundtrack, as well as several tracks on The Smashing Pumpkins Adore. He also worked with Pumpkins frontman Billy Corgan on the soundtrack for the movie Ransom and with Pumpkins guitarist James Iha on Iha's solo album Let It Come Down. In 1998, Walker's own band, Cupcakes, was signed to DreamWorks Records and subsequently left the Pumpkins to record the Cupcakes album. Matt was replaced by John Mellencamp's drummer, Kenny Aronoff, for the Pumpkins "Adore" tour. Walker did, however, play with the Pumpkins again at their final show on 2 December 2000 when he played percussion on an alternate version of the song "Muzzle" and drums on "1979", while the original drummer Jimmy Chamberlin played acoustic guitar. He once again rejoined the Pumpkins on percussion during the Chicago dates of their 20th anniversary tour in November and December 2008. Walker also performed with the Pumpkins at a benefit concert at the Metro in Chicago, in July 2010 for an encore of "1979."
Matt went on to other collaborative efforts including Ashtar Command with former Filter member, Brian Liesegang,and Chris Holmes. Matt co-created the band, impossible recording machine with Jim Dinou.
Walker was also a member of the band theMDR (the Most Dangerous Race), who appeared on the 2007 MySpace/SPIN Smashing Pumpkins tribute album performing "Signal to Noise," an unreleased Smashing Pumpkins song. While on hiatus from Morrissey, Matt writes songs and performs under the name "of1000faces" with various singers and musicians. Under his own name in 2009, Walker co-wrote with Adam Ant and Morrissey/Ant guitarist Boz Boorer, as well as drummed on, the track Marrying The Gunner's Daughter, the quasi-title track of Ant's 2013 album Adam Ant Is the Blueblack Hussar in Marrying the Gunner's Daughter.
Walker played drums with Morrissey since 2006, and played on his albums, "Years of Refusal", and "Swords". Walker ended his career with Morrissey following the 2012 tour in North America. Morrissey responded saying, "“Our little covered wagon has lost drummer Matt Walker, who was eager to bring his term to an end. No bargainings could persuade him to stay, and his interest drew its last breath at Stockton...Behind the kit, Matt was a greyhound unleashed, and his great work on Years of Refusal will always and forever speak up in his favor. His exit is sad, but he had no wish to continue, and a branch falls away.” On November 26, 2013, Walker announced on his Facebook page "i'm very happy to announce i will be drumming again for morrissey, beginning with a performance at the nobel peace prize ceremony in oslo, norway."