Ontario Premier Doug Ford was among those who offered his condolences.
"Canadian journalism has suffered a great loss today with the passing of Christie Blatchford," Ford tweeted Wednesday morning.
"My sincerest condolences to her family, friends, and fellow fans."
In a statement, Toronto Mayor John Tory called Blatchford a "giant in Canadian journalism."
"She worked tirelessly to shine a light on the justice system and how it works or sometimes doesn't work — always with a focus on getting the story right and getting people to do the right thing," he said.
"Christie was a tough, fair journalist who was strongly committed to print journalism — she worked at all four Toronto newspapers — and on the radio. She was courageous — never afraid to tell it as she saw it — and leaves behind a legacy of fearlessness that will hopefully inspire journalists for generations to come."
Toronto Superior Court Justice Michael Dambrot even made mention of Blatchford's death during a high-profile sentencing hearing Wednesday morning.
"Just before we rise, I want to personally acknowledge my sadness at the death of Christie Blatchford, who spent many days seated in my courtroom and who I believed to be a fearless journalist," Dambrot said.
In one of her final columns in October, Blatchford wrote about nagging muscle pain that forced her to leave the Liberals' federal election tour only six days in — a mysterious ache that kept her from logging her daily 10- to 15-kilometre runs and instead led to her diagnosis. The cancer had spread to bones in her hip before being detected.
Wrote for major newspapers
Blatchford moved to Toronto in high school, and started her career in The Globe and Mail's sports department, after being awarded the Joe Perlove Scholarship for graduating at the top of her journalism class at what was then Ryerson Polytechnical Institute in 1973.
She bounced around Canada's major newspapers in the coming years, starting with the Toronto Star in 1977 as a features writer, before moving to the Toronto Sun in 1982.
She wrote for the National Post from 1998 to 2003, before heading back for a stint at the Globe and Mail. Blatchford returned to the Post as a national columnist in 2011.
Then 24-year-old sports reporter Christie Blatchford discusses her love of sports, and calls politicians "a fat, dumb lot." 4:23
Her last column came in October, after the Liberals' federal election win.
"Where the results show most Canadians forgave Trudeau or moved on or simply didn't much care about airy-fairy concepts like prosecutorial independence, I could hardly believe that he kept emerging unscathed, that people weren't laughing out loud at his nose-stretchers, that the head-bobbers of his caucus kept at it so faithfully," Blatchford wrote.
"Clearly, I experienced the campaign and the election differently."
Blatchford was no stranger to awards. Her book Fifteen Days: Stories of Bravery, Friendship, Life and Death from Inside the New Canadian Army, won the Governor General's Literary Award in 2008. She won a National Newspaper Award for column writing in 1999.
Blatchford also won the George Jonas Freedom Award last June, which recognizes a person who has "contributed significantly to advancing and preserving freedom in Canada."
Criminal defence lawyer Marie Henein presented Blatchford with the award at a gala in Toronto, describing an unapologetic, tough-as-nails writer whose pieces captured the "humanity" of a courtroom.
"None of it is sugar-coated and why should it be? In these times more than ever, don't we need a good dose of unvarnished truth? Don't we need a good dose of Christie?" said Henein, who rose to national prominence as Jian Ghomeshi's defence lawyer, a trial that Blatchford covered extensively.
"While lawyers and judges may rail against what she writes sometimes — may get infuriated even — here's our dirty little secret, I'm going to share it with you: They all get nervous when she walks into court. We know she is there and everyone — every single one of them, every judge and every lawyer — reads her first. And they do it for one reason: Her opinion matters, her perspective matters."
Rehtaeh Parsons controversy
Her work also brought controversy. For example, a 2013 column about Nova Scotia teenager Rehtaeh Parsons, who was sexually assaulted and later took her life, drew considerable ire for what many saw as victim blaming. It led Parsons's mother to write a message to Blatchford on Facebook, calling the column a "biased, degrading and harassing article."
Her work also inspired a website and Facebook page dubbed "Fire Christie Blatchford" — essentially a repository for likeminded readers to quote the parts of her work they most despised while calling for her to be turfed.
After winning the George Jonas Award, Blatchford told the Post that ensuring truth trumps everything else.
"Freedom of the press, the freedom to cover things fearlessly — that is, without fear of offending your readers — is more important than ever," she said.
© CBC News