Is population countable or uncountable noun?

Answer 1

The noun 'population' is a countable noun; the plural form is populations.

example: The population of our town is small. The surrounding towns have populations much larger.

Answer 2

Well, isn't that a happy little question! "Population" is actually a countable noun. You can have one population, two populations, or even many populations. Just like how you can paint one tree, two trees, or a whole forest!