Is it ever grammatically correct to begin a paragraph with pronoun?

Yes, it is perfectly grammatically correct to begin a paragraph with a pronoun, as long as the pronoun has a clear antecedent (the word or phrase it refers to). The antecedent might be in the preceding sentence, the preceding paragraph, or even implied by the overall context.

For example:

* "He" strode confidently into the room, his eyes scanning the assembled guests. They sat silently, anticipating his announcement. (Here, "He" refers to a previously mentioned person, and "They" refers to the guests.)

However, starting a paragraph with a pronoun *can* sometimes be less clear or more abrupt than starting with a noun or noun phrase. Good writing often involves a balance between conciseness and clarity. If the antecedent is far away or unclear, beginning with a pronoun can make the writing harder to follow. In such cases, it's usually better to restate the antecedent or use a different sentence structure.