A left winger also capable of playing as an attacking midfielder or second striker, he is often regarded within the media as "Australia's finest soccer export",[6] despite his career being blighted with injury.

Former Middlesbrough midfielder-turned pundit Robbie Mustoe named Kewell as one of the greatest players he had played against but questioned his consistency and attitude after his initial injuries.

At age 14, Kewell travelled to Thailand, Italy and England with the successful Marconi under-14 team that had recently won the state titles.

At age 15, Kewell was offered the opportunity to travel back to England and trial with Premiership football club Leeds United for a period of four weeks as part of the Big Brother Movement in Australia.

[22][23][24][25] In 1997, Kewell was part of the Leeds United youth-team that claimed the 1996–97 FA Youth Cup final in a 3–1 aggregate win against Crystal Palace.

[29] The club, however, began to suffer financial difficulties and, by 2002–03, having sold many of their best players, Kewell's efforts in front of goal merely delayed Leeds' slide from being relegated from the Premiership.

[31] Having rejected more financially enticing offers from Milan,[28] Chelsea,[28] Manchester United,[28][32] Arsenal[28] and Barcelona,[28][33] Kewell moved to the club he supported as a boy, Liverpool, for the start of the 2003–04 season.

[36][37] In a related matter, Kewell sued Lineker in 2005 for defamation of character, but, with the jury unable to agree on a verdict, the parties had to settle out of court.

Kewell was controversially selected by manager Rafael Benítez ahead of the defensive midfielder Dietmar Hamann, signalling the club's intent to attack from the outset.

[45] Kewell's form for Liverpool in the 2005–06 FA Premier League season showed what he was truly capable of, scoring goals and plenty of assists, lending support to his assertion that his prior mediocre performance was the result of poor health rather than apathy.

[54] Speculation on whether he was to be selected in Liverpool's upcoming Champions League final in Athens rapidly became positive for Kewell after providing an excellent game against Charlton.

[57][58] Kewell put in a great performance by setting up two goals for Fernando Torres and Dirk Kuyt as Liverpool beat Marseille in impressive fashion 4–0 away victory to secure qualification to the knockout phase of the Champions League.

After his return, Liverpool manager Rafael Benítez stated on the club's website and to other members of the media that a new contract for Kewell to continue his career at Anfield was not out of the question.

[63] On 5 July 2008, reigning Turkish Süper Lig champions Galatasaray signed Kewell to a two-year contract, presenting him with the number 19 shirt.

[74] On 2 November 2008, Kewell scored his fourth league goal in Galatasaray's home win over Gaziantepspor, after a week full of overwhelming speculations in the Turkish media about his injury.

In a 2009–10 Turkish Cup play-off, Kewell scored in a 2–1 win against Bucaspor on 28 October 2009 to put the side into the group stage phase of the tournament.

[83] During the 2009–10 UEFA Europa League qualifying rounds, Kewell scored Galatasaray's second goal in a 4–1 away win against Israeli club Maccabi Netanya on 30 July 2009.

[107] Following a solid but not sensational season at Galatasaray, there had been continual speculation that Kewell could be heading back home to Australia, with the Newcastle Jets reportedly a keen investor.

[116] Kewell scored his first goal for the Victory from a penalty against Gold Coast United on 26 November 2011 at AAMI Park, Melbourne, after teammate Archie Thompson was brought down in the box in the first minute.

Kewell scored his fifth goal against Central Coast Mariners on 10 February from a cracking volley in the box which helped Melbourne get a crucial 2–1 win over the top side.

On 18 February, Kewell scored two goals at Suncorp Stadium to give Melbourne a hope of drawing against Brisbane Roar in a classic 3–2 loss.

[117] On 6 April 2013, Kewell signed to Al-Gharafa in the Qatar Stars League for the remainder of the 2012–13 season as an injury replacement for fellow Australian Mark Bresciano.

[125][126] On 19 October 2016, it was announced that Kewell had been chosen as the recipient of the Alex Tobin Medal, Australia's most prestigious football honour, for his achievements during the course of his career.

[127] Kewell became the third youngest player to debut for the Australia national team when he played against Chile on 24 April 1996, aged 17 years and 7 months.

He did not start for Australia in their second group match against Brazil, but again came on as a substitute, missing an early opportunity when Brazilian goalkeeper Dida punched the ball out dangerously.

[144] Due to suspected gout,[145][146] (later diagnosed as septic arthritis – a bacterial infection in the joints of his left foot[147]) Kewell was unable to play against Italy in the knockout stage, which saw Australia eliminated from the tournament after a 1-0 loss.

Asamoah Gyan went on to score the resulting penalty and the game was drawn 1–1,[159][160] severely damaging Australia's hopes of progressing past the group stage.

[162] After the match, Kewell said that he was devastated by the decision made by referee Roberto Rosetti and felt that the red card "killed" his World Cup dream.

[167] Kewell continued his fine form in the semi-final against Uzbekistan by opening the scoring in the first five minutes, helping his side to a 6–0 win and progress to the final,[168] where they were beaten 1–0 by Japan.

[186] On 18 June 2022, Kewell joined Scottish Premiership title holders Celtic as a first-team coach, under compatriot manager Ange Postecoglou.