Later years and break-up (1980–1983)
While Lynott searched for a permanent guitarist, he and the other members of Thin Lizzy, past and present, worked on Solo in Soho which was released in April 1980, and the next Thin Lizzy album, Chinatown. Lynott got married on 14 February, and his wife gave birth to a second daughter in July. Dave Flett had hoped to be made a permanent member of Thin Lizzy but Lynott chose Snowy White, who had played with Pink Floyd and Peter Green. Ure was still acting as a temporary keyboard player at gigs during early 1980, but was replaced by Darren Wharton in April, shortly after White joined the band. Wharton was only 18 at the time and was initially hired on a temporary basis. This new line-up completed the Chinatown album between short tours, and two singles were released from it. The first, "Chinatown", reached No. 21 in the UK, but the second, "Killer on the Loose", reached the top 10 amid much adverse publicity due to the ongoing activities of serial killer Peter Sutcliffe, known as "The Yorkshire Ripper".
Chinatown was finally released in October 1980, and reached No. 7 in the UK, but by this time Thin Lizzy albums were not even reaching the top 100 in the US. After a successful tour of Japan and Australia, the band undertook what was to be their final tour of the US in late 1980.
At the beginning of 1981, Lynott began work on his second solo album, using Thin Lizzy members among a large group of backing musicians. Around the same time, the band were recording material for the next Thin Lizzy album, and as before, the sessions seemed to merge to the extent that musicians were not always sure which album they were working on. Producer for the Thin Lizzy sessions, Chris Tsangarides, stated, "The feeling of confusion was in the air in that sometimes nobody knew if they were working on a Phil solo record or a Lizzy album." Snowy White had previously felt that, as a member of Thin Lizzy, he should have been paid as a session player to appear on Lynott's solo recordings.
In April 1981, the band's first 'greatest hits' album was released, and The Adventures of Thin Lizzy reached No. 6 in the UK, although a stand-alone single, "Trouble Boys", only reached No. 53, the band's worst chart placing since 1975. According to White and Wharton, Lynott was the only person who wanted to release it, and nobody else liked the song. "Trouble Boys" had even been pencilled in as the title for the new album, but the single's chart failure resulted in the song being dropped from the album and the title changed to Renegade. One highlight for the band at this time was headlining the first-ever Slane Castle concert on 16 August, with support from Kirsty MacColl, Hazel O'Connor and U2.
Lynott's second solo album, The Philip Lynott Album, was delayed until 1982 while Renegade was completed and released in November 1981. Renegade was not successful, only reaching No. 38 in the UK and No. 157 in the US. A single, "Hollywood (Down on Your Luck)", also flopped, although it did reach No. 24 on the US Mainstream Rock chart. Only two songs from the album were written solely by Lynott, with the other members of the band contributing more to the compositions. Both Gorham and Wharton have since stated their dissatisfaction with some of the songs, such as "Angel of Death", "Fats" and "Mexican Blood". Wharton was omitted from the band photos on the back of the record sleeve, despite the fact that he was by this time a permanent member of the band. "It hurt me a great deal", he later said.
The beginning of 1982 was marred by both Downey and Gorham having to take breaks from the European tour to recover from personal problems. Downey was involved in a fight in a nightclub in Denmark in February, and Gorham was suffering from drug-induced exhaustion. Downey missed five concerts, and was replaced by Mark Nauseef again for three of them, and by Mike Mesbur of support band The Lookalikes for the other two. In March, Gorham collapsed and returned home; eight concerts were performed as a quartet and six others were postponed.
Later in the year, Lynott went on a solo tour and released his second solo album, which did not sell particularly well. Snowy White left the band in August 1982, having tired of the disorganised schedules and Lynott's drug problems, although by his own admission he was too restrained and quiet to fit in well with his more raucous bandmates. White went on to achieve top ten chart success in the UK with his single "Bird of Paradise" in 1983. Long-time co-manager Chris O'Donnell also left at this time, later stating, "A once-brilliant band was turning to crap before my very eyes."
Lynott wanted to find a replacement for White before starting to record the next album, which would turn out to be the band's last. By September 1982, after some unsuccessful rehearsals with Dutch guitarist Adrian Vandenberg, he had settled on John Sykes who had been a member of Tygers of Pan Tang and recorded "Please Don't Leave Me" single with members of Thin Lizzy. Sykes co-wrote the first single from the album, "Cold Sweat", although the rest of the album had already been written. Thunder and Lightning was released in March 1983, and was much more successful than its predecessor, reaching No. 4 in the UK, although it charted even worse than its predecessor in the US, reaching only No. 159, making it the band's worst charting album in the US. Sykes' presence had rejuvenated the band musically, the composing credits were evenly shared, and the style had grown much heavier, veering towards heavy metal.
The tour to support the album was to be a farewell tour, although Lynott was not convinced that this would be the end of the band. Sykes wanted to continue, although Gorham had had enough. The tour was successful, and some concerts were recorded to compile a live album. Partway into the tour, many of Thin Lizzy's past guitarists were invited onstage to contribute to some of the songs they had originally recorded, the only exception being Snowy White, who reportedly declined the invitation. The album was released in October 1983 as Life, which included older performances of "Renegade", "Hollywood (Down on Your Luck)" and "Killer on the Loose", featuring White, and reached No. 29 in the UK. The tour continued while two more singles were released, the last of them, "The Sun Goes Down", only reaching No. 52 in August. Lynott also undertook another solo tour, accompanied by Downey and Sykes, under the name of The Three Musketeers.
After a difficult leg of the tour in Japan, where some members of the band had difficulty obtaining heroin, Thin Lizzy played their final UK concert before their break-up at the Reading Festival on 28 August 1983, which was eventually released in 1992 as their BBC Radio One Live in Concert album. The last concert came in Nuremberg on 4 September, at the Monsters of Rock festival, after which the band members went their separate ways.