The vaccine was also authorised in December for use in Canadians aged 16 and older.
Canada has become the first country to approve the use of the Pfizer-BioNTech vaccine for kids age 12 and up.
Health Canada Chief Medical Advisor Supriya Sharma told a news conference on Wednesday: "This is the first vaccine authorised in Canada for the prevention of Covid-19 in children and marks a significant milestone in Canada's fight against the pandemic.
"Having access to a safe and effective vaccine will help control the disease's spread to their families and friends, some of whom may be at higher risk complications."
Sharma added that the vaccination rollout will help children return to a "more normal life".
"It'll also support the return to a more normal life for our children who've had such a hard time over the past year," she added.
Data from a clinical trial in the United States with 2,000 youths, saw each participant receive two doses of the jab, which Sharma said demonstrated it is as safe for adolescents as it is for adults.
No cases of Covid-19 were recorded among the vaccinated children involved in the study.
In adults, the vaccine has been said to be at least 95% effective in preventing coronavirus infection.
Other manufacturers of the four vaccines approved in Canada such as AstraZeneca, Johnson & Johnson, and Moderna, are all currently planning their own studies on the impact of Covid-19 vaccinations for children.
Some of these studies include participants as young as six months old. Sharma said that Health Canada will accelerate reviews of those studies also.
Since the start of the pandemic, roughly 20% of all Covid-19 cases in Canada were in people under 19-years-old.
The United States is reportedly expected to authorise the Pfizer-BioNTech vaccine for use in 12-15-year-olds as early as next week.