A Francophone is a person who speaks French natively or by adoption (i.e., the person uses it in everyday life). As an adjective, it means French-speaking, whether referring to individuals, groups or places.
Francophone countries include France, Belgium, Canada, Switzerland, Haiti and the French West Indies, and several countries in Africa that are former French colonies. Collectively these countries are known as la Francophonie.
A related term is anglophone, which means English-speaking. In Quebec, the term allophone has also been coined, and means "has a native language other than English or French". All three words have crossed over into Canadian English, and are politically charged to some extent.
In Canadian English, you usually canot be both and Anglophone AND a Francophone, you have to choose (usually your most fluent language). Hence many people would only consider France as the only truly francophone country as other contries have French spoken by a minority of the population. By that definition, in Canada, Quebec would be considered the only francophone province even though over a million Canadians outside Quebec speak French (mainly in the border regions of Quebec)
See also