He started his professional career at South Melbourne and later played for the Scottish club Hearts before joining Leicester and then transferring to Leeds United.

[12] Kisnorbo performed like a seasoned veteran and cemented his spot at centre back as a youngster ahead of more experienced players at the club.

After much speculation, Kisnorbo made his move from South Melbourne to the Edinburgh-based Scottish Premier League club Hearts in July 2003, signing a two-year contract.

[13] Kisnorbo quickly became a regular for the first team where he made 48 appearances in two seasons, scoring his only league goal in a 2–1 win over Hibernian on 24 October 2004.

[20] He followed former Hearts boss Craig Levein, teammates Mark de Vries and Alan Maybury across the border to the Midlands club.

[6] However, a move back to defence resulted in a change in fortunes for Kisnorbo, and his partnership with then-teammate Paddy McCarthy was instrumental in helping Leicester avoid relegation to League One that season.

[23][24] Transfer speculation linked Kisnorbo to Wigan Athletic at the end of the 2005–06 season, but he decided to extend his stay with Leicester by signing a new three-year contract,[25] less than 12 months after joining the club.

[26] Kisnorbo began the 2006–07 season well, scoring two goals and putting in fine rear-guard displays against Coventry City and Southend United, helping the club survive relegation yet again.

[32] Joslin admitted his mistake,[7] and had the ban rescinded the following day after video replays showed Kisnorbo actually won the ball outside the penalty area.

It was reported on 28 April that manager Nigel Pearson told Kisnorbo he could leave on a free transfer the following summer as the club began their preparations for their Championship campaign the following season.

[45] Leicester on 29 May released Kisnorbo at the end of his contract, along with Paul Henderson, Marc Edworthy, Bruno Ngotty and Barry Hayles.

[46] Kisnorbo stated he was "very disappointed to have been released",[47] and made it clear that he wanted "to show Leicester next season what they are missing because I'm desperate to stay in the Championship.

"[53] Kisnorbo scored his first goal for Leeds against Millwall on his return to the starting lineup after missing the previous game against Norwich City having picked up an illness on international duty.

[57] Kisnorbo played against Manchester United when Leeds won 1–0 away at Old Trafford on 3 January in the FA Cup, during which he and Richard Naylor "bolted the door against the assaults of Wayne Rooney and Dimitar Berbatov",[58][59] after which he was described as a hero.

[60] Kisnorbo missed the Football League Trophy Northern Section Final first leg loss against Carlisle United with a calf injury.

Grayson confirmed that Kisnorbo was looking to return from his Achilles tendon rupture injury around December/January time meaning he would miss at least half of the 2010/11 season for Leeds.

[74] In Leeds' penultimate game of the season, against Burnley, Kisnorbo made the provisional squad but failed to make the substitutes bench.

[76][77] On 7 May, Kisnorbo was named on the bench for Leeds against Queens Park Rangers, the first time he was included in a matchday squad since suffering his ruptured Achilles tendon.

[80] With Kisnorbo only on a short term contract to prove his fitness, Crystal Palace and Brighton & Hove Albion were linked with signing the player.

[83] After completing his injury rehab in his native Australia, Kisnorbo returned to pre-season training for Leeds United a week later than his teammates.

[91] After starting in the 5–0 loss against Blackpool, Kisnorbo put in an impressive performance against his old side Leicester City on 6 November to help earn Leeds a clean sheet in a 1–0 win.

[103] Kisnorbo was part of Australia's 2001 Youth World Cup campaign, playing five matches for the under-20 team in Oceania qualifiers,[104] including a goal against Papua New Guinea.

[106] His performances in the under-20 level and his senior career at South Melbourne FC led to his first international appearance on 6 July 2002 against Vanuatu in Australia's first match of the 2002 OFC Nations Cup.

[108] He declined to join the "Olyroos" squad for an Olympic preparation tour in July, electing to concentrate on cementing a place at Hearts in the pre-season.

These performances led to his selection for the Australian 2007 AFC Asian Cup squad,[112] playing in the first two group matches against Oman[113] and Iraq.

[116] It was widely regarded that Kisnorbo's poor performance at the Asian Cup had ruined his chances of ever returning to international level, and he remained outside the Australian national squad for over two years, however, following admirable performances with his new club Leeds United, Kisnorbo regained his international place in 2009 and started in a 3–0 friendly win over Republic of Ireland on 12 August 2009, nearly scoring a goal in the 22nd minute when his header was saved at pointblank range by goalkeeper Shay Given.

Again, he was credited with instilling a tenacious work-rate and hardened sense of self-belief in a very young team, made up partly of the club's academy graduates.

[128] On 23 November 2022, Kisnorbo was announced as manager of French top division side, and fellow City Football Group club, Troyes.

After winning only twice in the first 15 games of the 2023–24 season and dropping to relegation zone in Ligue 2 as well, Kisnorbo left Troyes by mutual consent on 6 December 2023.

[132] After only seven league games, including 5 wins, one draw and a loss, Melbourne Victory announced that Kisnorbo had departed the club effective immediately on the 17th of December.