The noun diversity can be countable or uncountable. In more general, commonly used, contexts, the plural form will also be diversity. However, in more specific contexts, the plural form can also be diversities e.g. in reference to various types of diversities or a collection of diversities.

Is diversity plural or singular?

Singular. diversity. Plural. diversities. (countable & uncountable); (singular) Diversity is the property of having many different kinds of things or people.

Is diversity countable or uncountable noun?

/daɪˈvɜːrsəti/ (plural diversities) [uncountable, countable, usually singular] a range of many people or things that are very different from each other synonym variety. the biological diversity of the rainforests.