Speaking through an interpreter in Vancouver, Gorbachev said he respected the movement, but warned that unspecified "extremist elements" might try to hijack it.
"What we have to bear in mind is that there is a reason for such a protest," Gorbachev, 80, a Nobel Peace Prize laureate, said after a speech to high school students.
"When we see [Americans] protesting, I think that means a great deal."
Gorbachev reminisced about "perestroika," the period of reform in the 1980s he ushered in that culminated in the collapse of the communist superpower and end of the Cold War.
The Americans, he said, need to ensure that everything is right in their own country "before trying to put the house in order in other countries."
Better in Canada, says Jim Flaherty
In Ottawa, Finance Minister Jim Flaherty said the U.S. protesters decrying the income gap between rich and poor have a point.
At the same time, Flaherty suggested the situation was better in Canada, a view movement sympathizers dismissed as wrong-headed and self-serving.
"We have a progressive income tax, and it favours the people with lower incomes who are vulnerable," Flaherty said in Ottawa.
The Manhattan protests, which have spread across the U.S. and are due to arrive in Canada on the weekend, have taken aim at what they see as government-abetted corporate greed that has served only the interests of the richest elites.
The protesters say far too much wealth is concentrated in the hands of a few — the one per cent — while the vast majority — the 99 per cent — struggle to get by.
Chelsea Taylor, who is helping organize the Occupy Edmonton protest, rejected Flaherty's suggestion that Canada is much different from the U.S.
"Canada has an income inequality rate that is growing faster than the American rate," Taylor said from Edmonton.
"In the past few decades in Canada, the top third of all wealth gains in income have gone to the richest one per cent in Canada."
The finance minister also said government supervision and regulation of the country's banks helped avert the meltdown seen in the U.S. that sparked the global economic crisis and recession of the past few years.
"We do not have a situation in this country of financial institutions that are not acting in a prudent and responsible way," he said.
Taylor said Flaherty was taking too much credit.
"This is a conservative government that has been calling for American-style deregulation," Taylor said.
"We do have similar problems here of very corporate-friendly lawmakers and very corporate-friendly policies that do not really defend the interests of the 99 per cent."
Planned for Saturday
As part of a global protest sparked by the Occupy Wall Street movement, protests are planned for Saturday in Canadian cities such as Vancouver, Edmonton, Calgary, Winnipeg, Montreal and Halifax.
One of the largest is expected to be in Toronto, where protesters will take the message to the country's financial heartland.
John Clarke of the Ontario Coalition against Poverty rejected Flaherty's comments as provocative.
"The 28 per cent increase in the use of food banks since the system that he's so supportive of moved into crisis here in Ontario is one of the indications of the fact that Flaherty is wilfully ignorant when it comes to poverty," Clarke said.
"The poor are poor here in Canada as they are in the United States, and they're angry and they have a reason to be angry."