As per the Official Languages Act, French is one of Canada's two official languages. However, it is spoken by approximately 25% of Canada's population. That Act specifies that all the government services must be provided in both official languages all over the country.
Quebec is the only province where French is spoken almost everywhere. They even have a law (Loi 101) stating that French shall be the only official language in Quebec, meaning that every public communication/advertisement has to be done at least in French, that there are specific rules for those who want to attend English schools, etc.
Between one third to half of the people who live in the Maritimes (New Brunswick, Nova Scotia, Newfoundland and Prince-Edward-Island) speak French. In addition to that, there are many francophones in the south-east part of Ontario (mostly in the Ottawa surroundings because it's the National Capital Region) as well as in the surroundings of Edmonton (in Alberta, due to workers moving there for some industries). However, since most of these people are bilingual, they will use English even though they can speak French.
I'm a French Canadian.