The correct plural possessive form is “people’s.” The rule is to take the plural form of the noun and add an “‘s.” “Peoples'” is incorrect as the plural possessive form of “person.” In rare circumstances, you might find it works to refer to a group of people within a community.

People’s is the possessive of the word people — the plural of person. In contrast, peoples’ is the possessive of the word peoples — used to refer to groups of people. Both words are plural nouns, and both are in the possessive form.

People’s is the singular possessive form of people. Peoples’ is the plural possessive form of People. Peoples or People’s or Peoples’ are all pronounced the same way. Because “Peoples” is usually singular, people’s’ is usually correct. We use peoples when we want to make the word “people” plural.

The primary difference between people’s and peoples ‘ is the context in which they occur. People’s and peoples’ are possessive noun forms. While people’s is the possessive of the word people, peoples’ is the possessive of the word peoples – the plural of people.