"She was not just a great leader for Britain, but she was really one of those people who will be a truly historic figure, remembered for centuries to come," Prime Minister Stephen Harper told a news conference.
"I think if you look at the sweep of her life, what she did — not just in Britain, but what she did on the world stage — really laid the groundwork for the freedom and the prosperity and opportunity that so many people around the world enjoy today."
In an earlier written statement, Harper described Thatcher, who died Monday of a stroke at age 87, as having had "that rarest of abilities to herself personify and define the age in which she served."
"Indeed, with the success of her economic policies, she defined contemporary conservatism itself."
Liberal Bob Rae, while disowning Thatcher's politics, echoed that sentiment.
"Mrs. Thatcher served as British prime minister for more than a decade and in many ways defined conservative politics of her time," Rae said.
"Her sheer determination and tenacity were legendary and even political opponents had to admire her ability to stick to the path she set out for her party and her country."
Thatcher's economic policies might best be summed up in a line from "The Path to Power," the second volume of her memoirs.
"Government should create the right framework of sound money, low taxes, light regulation and flexible markets (including labour markets) to allow prosperity and employment to grow," she wrote.
Those are ideas that would fit right into Harper's low-tax, smaller government policies. They resonate with some members of his cabinet as well.
Foreign Affairs Minister John Baird, a longtime admirer known for having had a cat named Thatcher, tweeted his condolences from Israel, where he is on an extended Middle East tour.
"We have lost a legend and a true lady, an icon and a personal political idol," Baird wrote. Treasury Board Secretary Tony Clement described her as a source of inspiration in his youth.
A tweet from Veterans Affairs Minister Steven Blaney read, "The U.K. has lost a great leader and a great prime minister." Calgary MP Michelle Rempel said Thatcher inspired her to plunge into politics.
Even former prime minister Jean Chretien, who never shared her conservative ideals, recalled her fondly and noted that she helped spearhead an international conservative renaissance.
"There was a move back to the right when she was there, not only in Great Britain, and they have to give her a lot of credit for it," Chretien said.
"She was a very colourful and tough prime minister," he added. "As a politician I respected her. She was fighter. I respect that a lot."
While Thatcher the Conservative leader was the odd woman out on the right in the international scene when she came to power in 1979, she was soon joined by ideological cousins, including Ronald Reagan in Washington and Brian Mulroney in Ottawa.
"The world today has lost one of its giants," Mulroney said in a statement that described Thatcher as the most transformative British leader since Winston Churchill.
"Like every great leader, with strong convictions and a bold vision, she made enemies.... But in a series of visits to Canada she won many friends here. By her final visit in 1988 she was recognized as the founder of modern conservatism, a leader who had dragged her country from the brink of economic and social crisis, and a beacon of strong principled leadership to the world."
Gil Troy, a McGill University historian and author of a book on the Reagan era, which included both Thatcher and Mulroney, said Canadian politics still echo those times.
"She set the bar very high," Troy said. "She was the first; she really heralded a revolution that very much defined the 1980s, that Ronald Reagan followed, that Brian Mulroney followed, that really was very defining for that decade."
Troy said she also made a virtue of standing on principle despite popular opinion, a trait of which both Harper and Baird took note.
"This conservative government takes stands on foreign policy that are based on principle, whether or not they're popular in the international arena and sometimes even at home," Troy said.
"They are very much following the Thatcher model."
Harper recalled that Thatcher and Reagan, along with Pope John Paul II, played key roles in ending the Cold War.
"The era of peace and prosperity that followed the end of the Cold War must therefore rank as one of her great and lasting gifts to this generation."
Mulroney's memoirs speak highly of his relationship with Thatcher on a number of international issues, although they clashed repeatedly over the issue of sanctions against apartheid South Africa. He supported sanctions; she was opposed.
Thatcher, however, bolstered Mulroney when she visited Canada during the bitter free trade debate and strongly endorsed the idea in a speech to the House of Commons.
Harper said Thatcher's leadership was an example to the world, and he described the legendary British prime minister as deserving of the nickname "the Iron Lady."
He recalled meeting her in London in 2006, saying she offered wise and gracious advice.
Colin Brown, chairman of the National Citizens Coalition, called her a champion of freedom.
"Mrs. Thatcher was a magnetic personality," said Brown. "She was Churchill's successor as the de facto leader of free people everywhere."
NDP Leader Tom Mulcair, for his part, offered a terse, three-sentence comment on "one of the most influential British politicians and world leaders of the 20th century."