S Green writes:

Actually the most populous English speaking country is India.

India is not an English-speaking country; it is simply a country in which many
people are reasonably fluent in English, which is not the same thing. The
population is primarily rural and most people do not speak fluent English, or
any English for that matter. However, English is the most popular second
language AFAIK and is widely spoken to some extent among those with an
education. It is a useful language for communication between different
segments of Indian society, since there are 15 different languages that are
widely used in the country (Hindi is about one third of the total). Native
English speakers are rare.

The greatest population of native English speakers is in the United States.
Canadians speak essentially the same English and add to this total.