Clarkson, who coached Hawthorn to four premierships in an era-defining stint from 2005 until 2021, arrived at North as head coach amid great fanfare after being appointed in August 2022.
But he was unceremoniously axed, with a year to run on his contract, by North football boss Todd Viney, a close friend, and club president Sonja Hood.
Viney and Hood delivers the news to Clarkson on Tuesday before players, whose feedback formed part of a review that led the Kangaroos to conclude they needed a new coach, learned of the change at an impromptu meeting on Wednesday morning.
"He didn't see it coming," Viney told reporters.
"I know Clarko really well. He was frustrated. He's disappointed, he's a fighter."
Clarkson's departure comes despite the Kangaroos' improved season in 2026, when they finished 14th and claimed nine wins.
Viney noted there were "still some gaping holes in our game plan".
"If there was one thing Clarko did, he tried too hard to fix that. Therefore what happens is we get into more meetings, more information and players end up becoming a bit more confused," he said.
"The players have been very supportive of what Clarko has tried to produce ... (but) messages have become a little bit muddier and players feel they haven't been clear."
Hood, sitting alongside Viney at Wednesday's press conference, said Clarkson had been around "football long enough to know the reality of what heading into the last year of a contract would look like".
"He's upset," she said.
Hood insisted the club is yet to headhunt John Longmire or Adam Simpson, who like Clarkson are former North players.
Clarkson was contracted until the end of 2027, when his initial bumper five-year deal with the struggling Roos was due to end.
The 58-year-old, through his manager James Henderson, released a statement via social media.
"We set out to stabilise the club and lay the foundations for a return to playing deep in September," Clarkson said.
"The challenge was a difficult one that I embraced with my whole being.
"My family and I have been privileged to be involved in AFL football for over 40 years, but it is now time for a new chapter."
Hood, who declared Clarkson's appointment had not been an error, and Viney expanded on why the club moved on Clarkson.
"Having consulted widely across the club, it has become clear that Alastair no longer has the belief from enough people at the club that he is the right coach to take this group forward," Hood said.
"Once we knew that, it felt disrespectful to him to have him coach into 2027.
"We have made progress and won more games but we won't shy away from our desire to want more from this talented group. This is unashamedly a football decision.
"Alastair, of course, believes he can turn this around – that's part of what makes him so special. We don't agree with him."
In August, Clarkson said he wouldn't be pushing for a contract extension this off-season and was happy to wait it out.
The start of Clarkson's North tenure was quickly overshadowed by the emergence of the Hawthorn racism saga in September that year.
"That took enormous toll on him ... I'm not sure the scars have fully healed," Viney said.
Racism allegations against the club and Clarkson, his former assistant Chris Fagan and former welfare manager Jason Burt were aired publicly.
Clarkson, now-Brisbane Lions mentor Fagan and Burt all strenuously denied any wrongdoing, while an AFL investigation found no adverse findings against the trio in May 2023.
Hawthorn settled the Federal Court case with the affected Indigenous former players in November 2024.
The 58-year-old finishes at North with a 25 per cent winning record (20-1-61) from 82 games.
North Melbourne are the third club to part ways with their senior coach this year, after Carlton sacked Michael Voss and Essendon fired Brad Scott.
Premiership coaches Longmire and Simpson, both North greats who have been linked to coaching the Kangaroos in the past, are expected to front up for their regular appearances on Fox Footy on Wednesday night.
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