Gillan was born on 19 August 1945 at Chiswick Maternity Hospital. His father, Bill, was a storekeeper at a factory in London, who came from Govan, Glasgow and left school at 13, while his mother, Audrey, came from a family where she was the eldest of four children, who all enjoyed music and singing, and whose father had been an opera singer and amateur pianist. His sister, Pauline, was born in 1948. One of Gillan’s earliest musical memories was of his mother playing “Blue Rondo à la Turk” on the piano.

Gillan’s first attempt at a band was called Garth Rockett and the Moonshiners, and consisted of himself on vocals and drums, alongside guitarist Chris Aylmer, who later went on to work with Bruce Dickinson. The band covered songs such as Tommy Roe’s Sheila and The Shadows’ Apache. He discovered he couldn’t sing and play drums at the same time, so settled on the role of lead vocalist, performing regularly at St Dunstan’s Hall, the local youth club. He soon switched to another local band who also played at Dunstan’s Hall, Ronnie and the Hightones, who renamed themselves as the Javelins after he joined. The band played covers of Sonny Boy Williamson, Chuck Berry, Jerry Lee Lewis and Little Richard, and were early customers of then-local music shop owner Jim Marshall. The Javelins disbanded in March 1964, with guitarist Gordon Fairminer leaving to join what eventually became the group Sweet.

After the Javelins, Gillan joined a soul band, Wainwright’s Gentlemen, which included another future Sweet member, drummer Mick Tucker. The band recorded a number of tracks including a cover of The Hollies hit “Ain’t That Just Like Me”. Although the band played several local popular music venues, they did not find success, so in April 1965, he decided to join Hatch End based Episode Six.

By spring 1969, Deep Purple had had a top 5 US hit with “Hush”, but the band, particularly Ritchie Blackmore, Jon Lord and Ian Paice, decided their future lay in hard rock, rather than the psychedelic pop sound of the early band. In June 1969, Blackmore, Lord and Paice went to see Episode Six perform at a pub gig and subsequently offered Gillan the job as new lead singer, asking him if he also knew any good bassists. Since Glover was by this point a reasonably experienced songwriter, he was also recruited. They were both accepted into the band on 16 June 1969, replacing singer Rod Evans and bassist Nick Simper respectively. The old line up of Deep Purple continued to do several concerts until the end of the month, whereupon Evans and Simper were both fired by managers Tony Edwards and John Colletta after their last show on 4 July.

In 1970, Gillan received a call from Tim Rice, asking him to perform the part of Jesus on the original 1970 album recording of Jesus Christ Superstar, having been impressed with his performance on “Child in Time”. After rehearsing a few times with Rice and Andrew Lloyd Webber, he recorded his entire vocal contributions in three hours. He was subsequently offered the lead role in the 1973 film adaptation. Gillan demanded to not only be paid £250,000 for his role in the movie, but also insisted, without the consent of his manager, that the entire band be paid because filming would conflict with a scheduled tour. The producers declined, instead casting Ted Neeley in the Jesus role, and Gillan continued on in the band.

After 1971, particularly after the release of Fireball, Gillan started to become disillusioned with the workload of the band, who had not had any holiday since their initial rehearsals at Hanwell. He started drinking, and relationships between him and the rest of the band became strained, particularly with Blackmore. On 6 November 1971, he collapsed with hepatitis while waiting to board a plane in Chicago, cancelling the remainder of a US tour.

By December 1972, having recorded Machine Head, Made in Japan and the yet to be released Who Do We Think We Are with Deep Purple, Gillan finally decided the workload had driven him to exhaustion. Unlike some band members, he was unhappy about Made in Japan, and disliked live albums in general. He tended to go into the studio after the rest of the band had recorded and finished the backing tracks, particularly for Who Do We Think We Are, to lay down his vocals separately. He had been continually at loggerheads with Blackmore, disagreeing about music regularly, which culminated in Gillan writing “Smooth Dancer” about him. While on tour in Dayton, Ohio, he sat down and wrote a resignation letter to the band’s managers, stating he intended to leave the band, effective from 30 June 1973.

After his departure from Deep Purple, Gillan retired from performing to pursue various unsuccessful business ventures. These included a £300,000 investment in a hotel near Oxford. A second was the Mantis Motor Cycles project, which suffered from the collapse of the British motorcycle industry in the mid-1970s, culminating in Gillan being forced to file for liquidation. A more successful opportunity, however, came with his investment in Kingsway Studios in 1974. This led to a live performance at the Butterfly Ball on 16 October 1974, replacing Ronnie James Dio at the last minute.

In 1975, Gillan formed the Ian Gillan Band with guitarist Ray Fenwick, keyboardist Mike Moran, quickly replaced with Mickey Lee Soule and then Colin Towns on keyboards, Mark Nauseef on drums and John Gustafson on bass. Their first album, Child in Time, was released in July 1976, followed by Clear Air Turbulence in April 1977 and Scarabus in October. The sound of the band had a distinct jazz-rock aspect which, although interesting to Gillan, proved commercially unsuccessful, particularly since punk rock was popular at the time.

Gillan then formed a new band, simply called Gillan, retaining Towns (who would co-write most of the material), and adding guitarist Steve Byrd, bassist John McCoy and drummer Pete Barnacle. Byrd and Barnacle were quickly replaced by Bernie Tormé and by former Episode Six bandmate Mick Underwood, after Gillan saw Torme playing with his punk trio. This band had a more high-powered hard rock sound, and the release of Mr. Universe in October 1979 saw Ian Gillan back in the UK charts although the independent record company the album came out on – Acrobat Records – folded soon after the album was released, prompting a contract with Richard Branson’s Virgin Records.

In Christmas 1979 Gillan was visited by Blackmore, who offered him the position of lead vocalist in Rainbow. Gillan declined due to the smaller workload the band had compared to his own. However, the pair did jam together for three nights at Marquee Club – the first time the two men had shared a stage since 1973.

Gillan continued releasing Glory Road in 1980, which resulted in the band making the first of several appearances on Top of the Pops. He considered the album to be his best work since Machine Head nearly a decade earlier. Following subsequent album Future Shock, Torme was fired after missing an appearance on Top of the Pops, and was replaced by Janick Gers. Gers appeared on the band’s next two albums, Double Trouble and Magic.

In 1982 Ian Gillan announced the band would fold, as he needed to rest his damaged vocal cords. The rest of the band Gillan, particularly McCoy and Towns, were not happy at the sudden disbanding of the group so soon after the success of Magic, and sued Gillan for royalties.

In 1983, manager Don Arden invited Gillan to join Tony Iommi, Geezer Butler and Bill Ward, all founding members of Black Sabbath, to form a supergroup. Although the band had reservations, on 6 April 1983, it was formally announced that Gillan had replaced Ronnie James Dio in Sabbath. The group recorded Born Again at the Manor Studios in Oxfordshire. Ward recalled that he “didn’t particularly like some of the lyrics that Ian was bringing forward and putting into the songs. Not because Ian doesn’t write good lyrics or anything like that; I think Ian is an excellent performer, great singer and often at times I think his lyrics can be quite brilliant. But I just have a personal difference in what I like to hear in the way of lyrics, and so I felt terribly disconnected.”

After the disappointment of Black Sabbath, Gillan joined a reunited Deep Purple in April 1984, announcing their comeback on Tommy Vance’s radio show. The reformed band rehearsed in Stowe, Vermont and recorded the album Perfect Strangers which was followed by a highly successful world tour. Another studio album with this formation, The House of Blue Light followed in 1987 but Gillan was concerned with the final results, stating “There’s something missing in the overall album. I can’t feel the spirit of the band.”

Gillan was in a relationship with Zoe Dean from 1969 to 1978. They had known each other since his time in Episode Six. In 1984, Gillan married his girlfriend Bron, to whom he had dedicated “Keep It Warm” from Black Sabbath’s 1983 album Born Again. They have twice since renewed their marriage vows. Their daughter Grace Gillan is also working as a singer for the band Papa LeGal. Gillan lives near Lyme Regis, Dorset and has a home in southern Portugal.

This was followed by the live album Nobody’s Perfect in 1988. The live album also featured a studio re-recording of the 1968 hit “Hush” with Gillan on vocals, to commemorate Deep Purple’s 20th anniversary. (The original 1968 release had been sung by Rod Evans). Gillan later remarked that the album was “the embodiment of all the things wrong with Purple.”

In contrast to his experiences with Deep Purple in the 1970s, Gillan felt frustrated that the band were no longer working enough. To fulfill his contract with Virgin, he formed a side project with Glover, writing and recording songs which didn’t fit Purple’s established hard rock style, which resulted in the album Accidentally on Purpose. By 1989, tensions between Gillan and Blackmore had resurfaced, due to the former’s greater enthusiasm for touring and differences over the music – the song “Mitzi Dupree” on The House of Blue Light is the original demo as Blackmore refused to re-record it. This culminated in Blackmore calling a rehearsal session without Gillan. After an acrimonious argument Glover told Gillan, “Ian you’ve gone too far this time,” and he was fired.

Gillan has expressed particular fondness for Armenia and has maintained popularity there since Rock Aid Armenia in 1989, which has led to him forming the supergroup WhoCares as a side-project to Deep Purple. On 2 October 2009, in honour of the 20th anniversary of Rock Aid Armenia, Gillan together with Tony Iommi, Geoff Downes, and the project organiser Jon Dee were received by the Prime Minister of Armenia who awarded them with the republic’s Orders of Honour.

At the urging of Glover, Lord and Paice, who wanted him in the fold for the band’s 25th anniversary tour, Gillan rejoined Deep Purple in 1992 to record the album The Battle Rages On. Gillan was unhappy with working on the album, as it had already been partially completed with Joe Lynn Turner, and he was only required to write replacement lyrics and vocal melodies, which, unsurprisingly, drew criticism from Blackmore. Blackmore left Deep Purple after the European tour promoting the album in 1993. Gillan and Blackmore subsequently repaired their relationship with each other.

On 31 March 2006 Gillan appeared at the Tommy Vance tribute concert in London. He was accompanied by Roger Glover, Steve Morris, Dean Howard, Michael Lee Jackson, Harry James, Sim Jones and Richard Cottle.

In April 2006 Gillan released a CD/multimedia project to document his 44-year career called Gillan’s Inn. Tony Iommi, Jeff Healey, Joe Satriani, Dean Howard, as well as current and former members of Deep Purple such as Jon Lord, Roger Glover, Ian Paice, Don Airey and Steve Morse are featured on this 2006 CD and DVD. The project, produced by Nick Blagona, includes a re-recorded selection of his Deep Purple, Black Sabbath and solo tracks. At the same time as Gillan’s Inn, Gillan announced that his solo albums with the Ian Gillan Band and Gillan from the 1970s and 1980s would be re-issued late in 2006 and early 2007 through Demon Records.

Ian Gillan sang on two songs off the Jon Lord & Hoochie Coochie Men studio album, Danger. White Men Dancing, released in late 2007. On 2 April 2007 Gillan released a DVD Highway Star – A Journey in Rock. The DVD has 6 hours of footage including documentaries and music clips. This was followed in February 2008 by a double live album on Edel Records, Live in Anaheim that features Gillan and Deep Purple classic songs and several rarities. A companion DVD was released in May 2008.

On 3 May 2008 Ian Gillan performed at the Jeff Healey memorial concert in Toronto, Canada. He had previously played live with Healey in Toronto in February 2005. He released a studio album entitled One Eye to Morocco in March 2009.

In 2010, Ian Gillan met Tony Iommi, Nicko McBrain and Jon Lord, Mikko Lindström from HIM and Jason Newsted at a studio in London to finish recording a song called “Out of my Mind”, which was released the following year. This is for the benefit of the music school to be built in Gyumri, Armenia – a project Ian Gillan has been working on with others since his 1990 solo concerts in Yerevan.

In 2010 Ian Gillan hosted a documentary about the Polish composer and pianist Fryderyk Chopin in Poland directed by Jerzy Szkamruk. Chopin’s Story is about the rise of the composer and documents his Polish years. The film has won several international awards, including the Best Documentary award at Tourfilm International Festival in Florianopolis, Brazil. It was aired on the Polish channel Discovery Historia on 21 June 2011. It was subsequently released on DVD.

On the flight back from Armenia in 2011, after each receiving the Armenian Presidential medal of Honour, Gillan and Iommi decided to form the side project WhoCares for ad hoc recordings (and possible performances) dedicated to raising money for specific causes. On 20 September 2013 Ian Gillan participated in the opening of the Octet Music School in Gyumri. The Eastern Diocese of the Armenian Church of America named Ian Gillan as its 2014 “Friend of the Armenians” and presented him the award at the 112th Diocesan Assembly in New York City.