The drug maker announced the deal on Twitter, in both English and French. But it did not state the quantity it would supply.
The announcement was made an hour before markets opened and two hours before a scheduled announcement from the Canadian government.
Pfizer also last month inked a deal with the U.S. government to supply the first 100 million doses of the vaccine it is developing in December, in a partnership with BioNTech SE.
The Canadian deal appears to also be in collaboration with the biotechnology firm.