In his New Year's message released Wednesday, Johnston said he and his wife travelled the country in 2011 and found that Canadians are generous with their time and money.
"Whether it's because of the geography we share or the climate we endure, giving seems to crop up everywhere in our society," Johnston said.
"We are bound to one another. And every day, in countless ways large and small, Canadians demonstrate their gift for giving."
Johnston noted that more than 80 per cent of Canadians donate to a worthy cause every year, and 12 million Canadians spend more than two billion hours doing volunteer work.
"Those are impressive numbers and speak to the kind of people we are — and the kind of country we've built. We are a nation of barn raisers."
He said the holidays highlight the spirit of generosity.
"An everyday culture of giving is one of the defining features of successful societies everywhere. This has been the case throughout Canada's past, but we cannot take it for granted. Together, let us renew our gift for giving as we look to the future," Johnston said.
"By celebrating and encouraging volunteerism and philanthropy, by calling on that fundamental commitment from our fellow citizens, we build a smarter and more caring Canada, one barn at a time."
Johnston said he's looking forward to a number of milestones in 2012.
It will be the year when Canadians begin celebrating the coming diamond jubilee of the Queen.
Other important events include the 100th anniversary of the Grey Cup, donated by a former governor general, Lord Grey.