An international for a full decade, Ljungberg earned 75 caps and represented Sweden national team at UEFA Euro 2000, 2004 and 2008, as well as at the 2002 and 2006 FIFA World Cups.

Eriksson's impression of the youngster was that he was remarkably talented for his age and that he was considerate of other players, noting that Ljungberg would pass the ball to his friends, so that they would have a chance to score.

[13] At the age of 18, Ljungberg attended university to study information technology and economics, but he struggled to balance the hectic academic timetable with the physically demanding commitments of professional football.

After winning several trophies in his years with Halmstad, Ljungberg's star was on the rise with interest from Barcelona, Chelsea, Aston Villa, Parma and Arsenal.

Ljungberg proved himself without difficulty and scored on his debut on 20 September after coming on as a substitute against rival club Manchester United, the match ending 3–0.

[22] He was instrumental in Arsenal's 2–1 win against Liverpool at Anfield where he won a penalty which Thierry Henry scored and then he slotted in a sweet finish from a Pires cross.

[30] The following season (2004–05) Ljungberg played in his fourth FA Cup final, when he came on as a substitute and scored one of Arsenal's penalties in the shootout as they defeated Manchester United.

[32] Despite a persistent ankle injury, Ljungberg played for Arsenal in the 2–1 defeat by Barcelona in the Champions League Final in Paris on 17 May 2006.

[33] It was speculated in January 2007 that Ljungberg was being forced to leave Arsenal, after bosses became tired of a run of injuries restricting his play.

[36] In a game away at rivals Tottenham Hotspur on 21 April 2007 Ljungberg limped off with an injury in the first half, and this proved to be his final appearance for the club.

[38] On 23 July 2007, after nine years at Arsenal, Ljungberg joined London rivals West Ham United on a four-year contract.

[41] In his last game of the season, Newcastle United defender Steven Taylor accidentally landed on top of him while trying to jump over him, breaking his ribs.

On 30 May 2009, the Sounders drew their fifth match in a row, this time against the Columbus Crew, after Ljungberg missed a penalty kick in the 31st minute.

[58] Ljungberg scored his second goal for the season against the San Jose Earthquakes on 13 June 2009 as a result of beating Joe Cannon to the ball, lofting it over him and into the center of the net.

Ljungberg sat out for the US Open Cup game against the USL side Portland Timbers and focused on training during the four-week vacation in July.

Later, Ljungberg told reporters that he ingested trace amount of red wine while in Utah, resulting in his second migraine within months.

[65] Ljungberg was traded to Major League Soccer club Chicago Fire on 30 July 2010 in exchange for a second-round selection in the 2011 MLS SuperDraft.

[71] Ljungberg made his debut for Celtic away to Berwick Rangers in the Scottish Cup on 9 January 2011, playing over 60 minutes and helping his team to a 2–0 victory.

[74] Upon his release, Ljungberg was linked to Australian club Central Coast Mariners and South African team, Orlando Pirates.

[88] During an open team practice before the 2002 FIFA World Cup, Ljungberg broke into a fight with teammate Olof Mellberg following a robust tackle from the latter.

[89] The two of them were quickly separated by shocked teammates and the team practice was immediately cancelled to deal with the public relations disaster.

Prior to the finals, the team doctor Magnus Forssblad prohibited Ljungberg from participating in full-blown training between matches to protect his injured foot.

[citation needed] Despite being advised to take time off, Ljungberg insisted on playing in the cup to help Sweden win.

[citation needed] Sweden's weak start was quickly forgotten after their victory against Paraguay in the 2006 FIFA World Cup.

[94] He captained the side in eight of the nine UEFA Euro 2008 qualifiers including games against Latvia, Liechtenstein, Spain, Northern Ireland, and Iceland.

[4] After the appointment of Andries Jonker as the new manager for VfL Wolfsburg on 27 February 2017, the club announced later the same day that he would be assisted by Ljungberg and Uwe Speidel.

[103] His first match as interim head-coach ended in a 2–2 draw away to Norwich City on 1 December, and he achieved his first and only win, beating West Ham United 3-1 eight days later.

[106] On 22 August 2020 Ljungberg announced his departure from his first team assistant coaching role at Arsenal to progress his management experiences and pursue new opportunities.

In a global Nike advertising campaign in the run-up to the 2002 World Cup in Korea and Japan, he starred in a "Secret Tournament" commercial (branded "Scorpion KO") directed by Terry Gilliam, appearing alongside football players such as Ruud van Nistelrooy, Thierry Henry, Ronaldo, Edgar Davids, Fabio Cannavaro, Francesco Totti, Ronaldinho, Luís Figo and Hidetoshi Nakata, with former player Eric Cantona the tournament "referee".

[111][112] Ljungberg, who rarely talks about his personal life in the media, married long-time partner Natalie Foster, whom he met in 2007, on 9 June 2014 at a ceremony in front of the Natural History Museum.