Editing Def Leppard (section)

== Side projects ==
Phil Collen played guitar, uncredited, on [[Sam Kinison]]'s "Wild Thing" in 1988. The video featured members of bands such as [[Poison (American band)|Poison]], [[Bon Jovi]], [[Mötley Crüe]], [[Guns N' Roses]], [[Ratt]], and [[Aerosmith]].<ref>{{cite web |title=Exclusive Interview: Phil Collen on Manraze and Def Leppard Legacy |url=https://ultimateclassicrock.com/def-leppard-phil-collen-manraze-interview/ |website=Ultimate Classic Rock|date=31 July 2011 }}</ref> Collen also produced and played on the 1991 album ''On the Edge'' by Australian band [[BB Steal]].<ref>{{cite web |title=BB Steal |url=https://www.melodicrock.com/tags/bb-steal |website=MelodicRock.com}}</ref>

Joe Elliott sang lead vocals on two tracks on [[The Rolling Stones|Rolling Stones]] guitarist [[Ronnie Wood]]'s 1992 solo album, ''[[Slide on This]]''. His then-wife Karla appeared in the videos for "Always Wanted More" and "Somebody Else Might". Various members of Def Leppard have played on tribute records for [[Jeff Beck]], [[AC/DC]], and [[Alice Cooper]].{{Citation needed|date=February 2019}}

A fan of his local football club [[Sheffield United F.C.]], Elliott performed on two tracks to the soundtrack of the 1996 Sheffield-set motion picture, ''[[When Saturday Comes (film)|When Saturday Comes]]'' (featuring fellow Sheffield native [[Sean Bean]] as a star football player), the title track and an instrumental, "Jimmy's Theme".<ref name=NYT>{{cite web|title=When Saturday Comes|url=https://www.nytimes.com/movies/movie/136095/When-Saturday-Comes/overview|archive-url=https://web.archive.org/web/20150623185419/http://www.nytimes.com/movies/movie/136095/When-Saturday-Comes/overview|url-status=dead|department=Movies & TV Dept.|work=[[The New York Times]]|first=Michael |last=Betzold|date=2015|archive-date=23 June 2015}}</ref> Elliott sang and co-wrote the opening track, "Don't Look Down" on Mick Ronson's farewell album ''Heaven and Hull''. A promotional video was issued for the song as well.<ref>{{cite web |title=Def Leppard's Joe Elliott Releases Video Tribute To Friend Mick Ronson |url=https://www.udiscovermusic.com/news/def-leppards-joe-elliott-releases-video-tribute-friend-mick-ronson/ |website=U Discover Music |date=27 August 2018 |access-date=2 February 2020}}</ref>

[[Cybernauts]] was a side project consisting of Elliott and Collen teamed with members of [[The Spiders From Mars]] ([[David Bowie]]'s former band), minus the late [[Mick Ronson]]. The group played several shows, covering Bowie's [[David Bowie|Ziggy Stardust]]-era songs and released one internet-only album (since deleted).<ref>{{cite web |title=DEF LEPPARD Members' CYBERNAUTS Planning Digital Album Release |url=http://bravewords.com/news/def-leppard-members-cybernauts-planning-digital-album-release |website=Brave Words}}</ref>

[[Vivian Campbell]] has played with two side bands in recent years, [[Clock (American band)|Clock]] and the [[Riverdogs]], and recorded a solo album, ''Two Sides of If'', released in 2005. Campbell toured with [[Thin Lizzy]] in early 2011 before joining Def Leppard on their Mirrorball tour.<ref>{{cite web |title=DEF LEPPARD Guitarist Vivian Campbell On New THIN LIZZY Album |url=http://bravewords.com/features/def-leppard-guitarist-vivian-campbell-on-new-thin-lizzy-album-thats-what-were-talking-about-but-its-kind-of-a-grey-area-as-to-what-the-future-holds |website=Brave Words |access-date=2 February 2020}}</ref>

Collen sings lead vocals and plays guitar in a side band called [[Man Raze]] with [[Sex Pistols]] drummer [[Paul Cook]] and former [[Girl (band)|Girl]] bandmate [[Simon Laffy]]. They released their debut album ''[[Surreal (album)|Surreal]]'' in 2008 and a second album, ''[[PunkFunkRootsRock]]'', in 2011.<ref>{{cite magazine |title=Def Leppard, Sex Pistols Members Team for Man Raze |url=https://www.rollingstone.com/music/music-news/def-leppard-sex-pistols-members-team-for-manraze-ep-premiere-242755/ |magazine=Rolling Stone|date=7 November 2013}}</ref>

Joe Elliott founded and fronts the band [[Down 'n' Outz]] with members of [[The Quireboys]]. The band plays covers of [[Mott the Hoople]] and related artists such as [[British Lions (band)|British Lions]] and [[Ian Hunter (singer)|Ian Hunter]]. They have released two studio albums of covers, one of original material and one live album since their incarnation in 2009.<ref>{{cite web |title=Def Leppard Singer's Down 'N' Outz Is Working On Its First Album of New Material |url=https://www.blabbermouth.net/news/def-leppard-singers-down-n-outz-is-working-on-first-album-of-original-material/ |website=Blabbermouth|date=25 December 2017}}</ref>

Following the death of [[Ronnie James Dio]], Vivian Campbell reunited with the rest of the original [[Dio (band)|Dio]] line-up with vocalist [[Andrew Freeman (musician)|Andrew Freeman]] to form [[Last in Line]]. The band pays tribute to Dio by playing songs from their original tenure in the band and released an album titled Heavy Crown in February 2016.<ref>{{cite web |title=Vivian Campbell Compares Def Leppard to His Side Band 'Last In Line' |url=https://metalheadzone.com/vivian-campbell-compares-def-leppard-to-his-side-band-last-in-line/ |website=Metal Head Zone |date=4 March 2019 |access-date=24 June 2019 |archive-date=25 October 2020 |archive-url=https://web.archive.org/web/20201025113526/https://metalheadzone.com/vivian-campbell-compares-def-leppard-to-his-side-band-last-in-line/ |url-status=dead }}</ref>

Joe Elliott, along with various other musicians including [[Glenn Hughes (English singer)|Glenn Hughes]], [[Duff McKagan]], [[Sebastian Bach]], [[Matt Sorum]], [[Gilby Clarke]] and [[Steve Stevens]] formed a [[Supergroup (music)|supergroup]] called [[Kings of Chaos (band)|Kings of Chaos]], whose catalogue consists of songs by [[Deep Purple]], Def Leppard, [[Guns N' Roses]] and others. In 2012, Kings of Chaos recorded their version of Deep Purple's classic, "Never Before" featuring Elliott singing lead vocals. Kings of Chaos played Stone Fest in Australia along with a few dates in South America in 2013.<ref>{{cite web |title=DEF LEPPARD's Joe Elliott Talks KINGS OF CHAOS—"We're Just A Group of Old Friends Getting Together to Make Music" |url=http://bravewords.com/news/def-leppards-joe-elliott-talks-kings-of-chaos-were-just-a-group-of-old-friends-getting-together-to-make-music |website=Brave Words}}</ref>

Phil Collen formed a blues project by the name of Delta Deep with vocalist Debbi Blackwell Cook which released an eponymous debut in 2015.<ref>{{cite web|last1=DeRiso|first1=Nick|title=Def Leppard's Phil Collen Announces Blues-Rock Side Project Delta Deep|url=http://ultimateclassicrock.com/phil-collen-delta-deep/|website=Ultimate Classic Rock|date=28 December 2013 |access-date=20 January 2016}}</ref>

In October 2020, Joe Elliott and Phil Collen played on [[the Struts]] song, "I Hate How Much I Want You", part of their ''Strange Days'' album.<ref>{{cite web |title=How British rockers the Struts made an 'Exile on Main Street' for the COVID age |url=https://www.yahoo.com/entertainment/how-british-rockers-the-struts-made-an-exile-on-main-street-for-the-covid-age-055445048.html |website=www.yahoo.com|date=17 October 2020 }}</ref>