The stamp — which depicts a heart surrounded by hands of different colours — carries a 10-cent surcharge on top of the regular 61-cent postage cost.
Those additional funds will go towards charities and school programs that help children overcome the barriers that prevent them from leading a happy and healthy life, Canada Post says.
Customers will also be encouraged to make donations at their local post office.
The stamp, developed and released by the organization's Community Foundation for Children on Monday, represents a key element in the 2012 fundraising campaign.
The foundation has raked in $7 million over its brief four-year history.
Canada Post chief executive Deepak Chopra says the 2011 campaign raised $2 million, which will be dispersed among 44 charities in the coming months.
"People think that donations have to be larger but with 10 cents, you can change a child’s future," Chopra told a news conference.
Sharon Wood, president of the Canadian arm of Kids Help Phone, said Canada Post's fundraising efforts have made a daily difference to the children her organization serves.
"Every week over 5,000 kids reach out to Kids Help Phone" she said. "And Canada Post has helped make sure that they can be heard."
The 2012 stamp was designed by professionals, but Canada Post announced that next year's version will be created by the people who will benefit from it most. The foundation will pick the stamp’s new design from a contest for Canadian children.