Numan came to prominence in the 1970s as lead singer, songwriter, and record producer for Tubeway Army. After recording an album's worth of punk-influenced demo tapes (released in 1984 as The Plan), they were signed by Beggars Banquet Records in 1978 and quickly released two singles, "That's Too Bad" and "Bombers", neither of which charted.

A self-titled, new wave-oriented debut album later that same year sold out its limited run and introduced Numan's fascination with dystopian science fiction and synthesisers. Though Tubeway Army's third single, the dark-themed and slow-paced "Down in the Park" (1979), never appeared on the charts, it became one of Numan's most enduring and oft-covered songs. It was featured with other contemporary hits on the soundtrack for the 1980 film Times Square, and a live version of the song can be seen in the 1982 film Urgh! A Music War. Following exposure in a television advertisement for Lee Cooper jeans with the jingle "Don't Be a Dummy", Tubeway Army released the single "Are 'Friends' Electric?" in May 1979. The single and its parent album both reached No. 1 in the UK charts at the end of June.

At this point Numan was already busy recording his next album with a new backing band. At the peak of success, Numan opted to premiere four new songs in a John Peel session in June 1979 rather than promoting the current album and the Tubeway Army group name was dropped.

In September "Cars" also reached No. 1 in the UK. The single also found success in North American charts where "Cars" spent 2 weeks at No. 1 on the Canadian RPM charts, and reached No. 9 in the U.S. in 1980. "Cars" and the 1979 album The Pleasure Principle were both released under Numan's own stage name. The album reached number-one in the UK, and a sell-out tour (The Touring Principle) followed; the concert video it spawned is often cited as the first full-length commercial music video release. The Pleasure Principle was a rock album with no guitars; instead, Numan used synthesisers fed through guitar effects pedals to achieve a distorted, phased, metallic tone. A second single from the album, "Complex", made it to No. 6 on the UK Singles Chart.

Numan subsequently issued a series of albums and singles on his own record label, Numa. The first album released on Numa, 1984's Berserker was also notable for being Numan's first foray into music computers/samplers, in this case, the PPG Wave. The album was accompanied by a new blue-and-white visual image (including Numan himself with blue hair), a tour, a live album/video/EP, and the title track reached the UK top 40 when released as a single. Despite this, the album divided critics and fans and commercially it was Numan's least successful release to that point.

A collaboration with Bill Sharpe of Shakatak as Sharpe & Numan in 1985 was more successful. In March the single "Change Your Mind" reached No. 17 on the UK Singles Chart. A few months later the live album White Noise recorded during the Berserker Tour and a live EP with tracks taken from it reached No. 29 and 27 respectively on the charts.


Andre Csillag taking group photos of the band for the Official Fury Tour book; Manchester Apollo, October 1985
Numan's next album, The Fury (1985), charted slightly higher than Berserker, breaking the top 30. Again, the album heralded a change of image, this time featuring Numan in a white suit and red bow tie. The three singles released from the album ("Your Fascination", "Call Out the Dogs" and "Miracles") all charted in the top 50 on the UK charts.

In 1986 Numan scored two top 30-hits on the UK Singles Chart with "This Is Love" in April and "I Can't Stop" in June, but the album Strange Charm released later that year only spent two weeks on the album chart, peaking at No. 59. In November a version of the song "I Still Remember" from the previous album was released as a charity single and stalled at No. 74 on the singles chart.

Further collaborations with Bill Sharpe spawned two more Sharpe & Numan chart hits with "New Thing from London Town" at No. 52 in 1986 and "No More Lies" at No. 35 in 1988. In 1987, Numan performed vocals for three singles by Radio Heart, a project of brothers Hugh and David Nicholson, formerly of Marmalade and Blue, which charted with varying success ("Radio Heart" No. 35 UK, "London Times" No. 48, "All Across the Nation" No. 81). An album was also released, credited to "Radio Heart featuring Gary Numan" although Numan only appeared on three tracks, but failed to chart. Also in 1987, Numan's old label Beggars Banquet released the best-of compilation Exhibition, which reached No. 43 on the UK Albums Chart, and a remix of "Cars". The remix, titled "Cars (E Reg Model)" charted at No. 16, Numan's final top 20 hit until the 1996 rerelease of the same song.

Numa Records, which had been launched in a flurry of idealistic excitement, folded after the release of Numan's 1986 album Strange Charm. Numan would reopen the record label in 1992, but it was again shuttered in 1996. In addition to Numa Records' commercial failure, Numan's own fortune amassed since the late 1970s, which he estimated at £4.5 million, was drained. Numan then signed to I.R.S. Records through his final studio album of the 1980s, Metal Rhythm (1988), which also sold relatively poorly. For its American release, the record label changed the album's title to New Anger after the album's lead single, changed the album colour from black to blue, and remixed several of its tracks against Numan's wishes. In 1989, the Sharpe & Numan album Automatic was released through Polydor Records, though this too failed to garner much commercial success, briefly entering the charts and peaking at No. 59.

Numan performing in 2011
In a September 2009 interview with The Quietus, Numan said that he and Trent Reznor planned to make music together.

Numan was set to perform a small number of American live dates in April 2010, including a Coachella Festival appearance in California, but had to cancel because air travel in Europe was halted by the Icelandic volcanic ash cloud. As a result, the tour was not only postponed but expanded, and his Pleasure Principle 30th Anniversary Tour's American and Mexican dates began on 17 October 2010, at Firestone Live in Orlando, Florida.

Numan toured Australia in May 2011 performing his seminal album The Pleasure Principle in its entirety to celebrate its thirtieth anniversary. Joining him on tour was Australian electronic band Severed Heads, coming out of retirement especially for the shows.

Numan lent his vocals to the track "My Machines" on Battles's 2011 album Gloss Drop. He was chosen by Battles to perform at the ATP Nightmare Before Christmas festival that they co-curated in December 2011 in Minehead, England. Numan's album Dead Son Rising was released on 16 September 2011 which had a full UK tour split in two-halves, 15-21 September and 7-11 December, Both parts were supported by Welsh soloist Jayce Lewis in an interview during the tour; Numan praised Lewis for being the best supporting act ever in his 30 years of touring, later documenting the tour in a tour diary and publicly inviting Lewis to join him for an American tour in 2012.

Numan also provided narration for Aurelio Voltaire's short film Odokuro in 2011.

While working on a new album due for release in 2013, Numan said "The one I'm working on now which I'm trying to get out in the middle of next year. It's very heavy, very aggressive and very dark. There are elements of Dead Son Rising in that, but it's much further along that particular road."

The album Splinter (Songs from a Broken Mind), was released on 14 October 2013. It reached the UK Top 20, his first album to do so for 30 years. It was promoted by an extensive US, Canada, UK & Ireland tour which continued in 2014 to include Israel, New Zealand, Australia and Europe. A further US leg took place in late 2014.


Numan performing at South by Southwest in 2014
In June 2014, Numan collaborated with Jayce Lewis and his Protafield project on the track "Redesign" featured on Protafield's Nemesis Album.] Numan also provided vocals for the song "Long Way Down" composed by Masafumi Takada with lyrics written by Rich Dickerson for the video game The Evil Within. The game was released on 14 October 2014. Numan performed a sold-out, one-off live show in London in November 2014 at the Hammersmith Apollo supported by Gang of Four.

On 29 April 2015, Numan announced via his Facebook page that he had begun writing songs for the follow-up album to Splinter (Songs from a Broken Mind).

Numan collaborated with the industrial pop group VOWWS for "Losing Myself in You" on their debut album The Great Sun.

On 6 May 2016, Numan was one of several collaborators on Jean-Michel Jarre's album Electronica 2: The Heart of Noise, with the track "Here for You", cowritten by Jarre and Numan.

On 10 May 2016, Numan was named the recipient of the 2016 Moog Innovation Award by Moog Music. On 18 May 2017, Numan received an Ivor Novello Inspiration Award from the British Academy of Songwriters, Composers, and Authors.

In 2017, Numan released the single "My Name Is Ruin" and went on a European tour September. Numan's album Savage (Songs from a Broken World) was released on 15 September and charted at number two in the UK. He was the winner of the 2017 T3 tech legends award.

On 24 September 2018, Numan's tour bus hit and killed an elderly man in Cleveland, Ohio, US. The driver was not immediately charged. Numan was scheduled to appear at the Cleveland House of Blues that evening but cancelled the show for being "inappropriate" in light of the day's tragedy. Numan posted on Twitter later in the day, saying, "We are all utterly devastated by the fatal accident involving our tour bus in Cleveland earlier today. Everyone of us is filled with a sadness that made it impossible to even consider playing our show this evening, and out of respect it would have been entirely wrong. I'm sure you can understand why we cancelled and I apologize to the House of Blues and to the fans for any difficulties or disappointment this decision may have caused. All tickets will be honored at the point of purchase. At the moment all we can think about are the people affected by this terrible tragedy and to them we send all our love."

On 2 May 2019, Numan announced the working title of his next album as Intruder. The album was officially announced alongside its tracklist on 8 January 2021, and was released on 21 May 2021. The title track was released earlier, on 11 January 2021. Numan discussed its genesis with author Guy Mankowski, who has a chapter on Numan's legacy in his book Albion's Secret History: Snapshots of England's Pop Rebels and Outsiders, as part of an interview series on influential English artists for Zer0 Books.

In the late 1970s, Numan began developing his style. According to Numan, this was an unintentional result of acne; before an appearance on Top of the Pops, "I had spots everywhere, so they slapped about half an inch of white make-up on me before I'd even walked in the door. And my eyes were like pissholes in the snow, so they put black on there. My so-called image fell into place an hour before going on the show." His "wooden" stage presence was, in his words, a result of "incredible self-consciousness" and "incompetence – I didn't know to move on stage". He became enamoured by the idea of "being cold about everything, not letting emotions get to you, or presenting a front of not feeling".

A prolific songwriter, Numan has written about 400 songs. His starting point is usually a piano to work out melodies and chord structures. Most of the songs on his early albums were written on a piano his parents had bought him: later in his career he has used a piano preset on the computer as a starting point. His biggest hit "Cars" was however unconventionally written on a bass guitar.

Numan's signature sound consists of heavy synthesiser hooks fed through guitar effects pedals.] He is also known for his distinctive voice and androgynous "android" persona.

Numan is an atheist. He was an outspoken supporter of the Conservative Party and Margaret Thatcher after her election as Prime Minister. He later expressed regret for giving his public support, calling it "a noose around my neck". He has previously said that he considers himself neither left- nor right-wing and that he did not support Tony Blair or David Cameron. He also said, "I'm not socialist, I know that. I don't believe in sharing my money."

In 1997, Numan married Gemma O'Neill, a member of his fan club from Sidcup. They have three daughters named Raven, Persia, and Echo. Persia, at the age of 11, contributed vocals to Numan's 2017 song "My Name Is Ruin" and appeared in its video. Numan and his family lived in Essex, then Heathfield and Waldron, and in October 2012 moved to Santa Monica, California.

At age 15, after a series of outbursts in which he would "smash things up, scream and shout, get in people's faces and break stuff", Numan was prescribed antidepressants and anxiolytics. In the 1990s, his wife suggested he had Asperger syndrome; after reading about the syndrome and taking a series of online tests, he agreed, though at the time he said he had not been officially diagnosed. Conversely, he said in an April 2018 interview with The Guardian that he had been diagnosed with Asperger syndrome at the age of 14. In a 2001 interview, he said, "Polite conversation has never been one of my strong points. Just recently I actually found out that I'd got a mild form of Asperger's syndrome which basically means I have trouble interacting with people. For years, I couldn't understand why people thought I was arrogant, but now it all makes more sense."

Numan published his autobiography, Praying to the Aliens, in 1997 (updated in 1998), in collaboration with Steve Malins, who also wrote the liner notes for most of the CD reissues of Numan's albums in the late 1990s, as well as executive producing the Hybrid album in 2003.

An updated autobiography, (R)evolution: The Autobiography, was published on 22 October 2020 and brings his career up to date from the earlier Praying to the Aliens .

$8 Million.