"He was a source of strength and financial leadership for the country during what was probably the most challenging economic period since the Great Depression," said Gord Nixon, the head of Royal Bank of Canada (TSX:RY).
"(Flaherty) provided great global leadership. I think he would be recognized by his peers as not just a source of strength to Canada, but a leading voice."
Flaherty, 64, a father of triplet sons, died suddenly Thursday at his Ottawa home, less than a month after he retired as the Harper government's first and only finance minister.
He spent eight years in the job, helping bring the economy through the banking collapse on Wall Street and the fallout from the disaster.
"My thoughts go to his wife, to the boys," International Monetary Fund managing director Christine Lagarde said in Washington, where Flaherty was a fixture at G20 and IMF meetings.
"We had a chat in Sydney, and a laugh. I would never have imagined he wouldn't be with us. He was a friend."
As finance minister, Flaherty opened the spending taps during the economic crisis, running a $56-billion deficit, bailing out the auto sector and boosting the ailing economy.
He also became a leading voice during the global financial crisis and earned international recognition.
In recent years, he returned to his fiscal conservative roots with tighter spending intended to help return the federal budget to a surplus.
Nixon said Flaherty wasn't always easy to deal with because he "didn't always see eye-to-eye" with banking executives, though they knew he was fair.
Flaherty rankled the Canadian investment community when he backed away from a campaign pledge by taxing income trusts like corporations.
He also took heat when he publicly chided Bank of Montreal (TSX:BMO) last year for lowering the its key five-year mortgage rate, warning the super-low rate could help overheat the housing market.
"There were certainly areas where we had different views, but I think he was balanced in terms of his approach," Nixon said.
Bank of Canada governor Stephen Poloz said Flaherty left an important legacy of "fiscal responsibility and public service."
"He devoted his life to Canada and Canadians," Poloz said in a statement.
John Manley, the head of the Canadian Council of Chief Executives called Flaherty an "extraordinary public servant."
"His astute judgment, thoughtful pragmatism and strength of character inspired confidence during a period of profound uncertainty and economic risk," said Manley, who was also a former deputy prime minister.
Dan Kelly, president of the Canadian Federation of Independent Business, described Flaherty as a "pragmatic politician" who saw his position as one that could make change.
"He recognized that being a politician was about more than passing laws and regulations," said Kelly.
"He used the full scope of his office to effect change right up to the very end," said Kelly.
"That was a rare quality in Ottawa. It was a rare quality for politics."
Former Canwest chief executive Leonard Asper said from his interactions, mostly at social events, Flaherty was an "extremely down to earth guy."
"He didn't run around with entourages, and he was very comfortable just talking to anybody," he said.
Robert Kennedy, dean of the Richard Ivey School of Business, remembered a speech Flaherty gave to students at the school in 2011 where he encouraged them to enter public service.
"(He said) 'You will have opportunities to change the world around you in varying ways and to different degrees, large and small. It is the most satisfying and personally enriching career you will ever find,'" Kennedy recalled Flaherty saying.
Former Bank of Canada governor Mark Carney said Flaherty had an "enormous influence" on global policy and on him personally.
"He was a man of principle who believed in fixing banks when they were broken, sound money and balanced budgets," said Carney, who now heads the Bank of England.
"I know many colleagues will feel his loss and I will miss him tremendously."