Hershey's is a proper noun used to refer to the Hershey Company or its products (notably chocolate). In everyday speech, it’s commonly pronounced as a possessive or brand name, typically with a stressed first syllable and a softened final consonant, and may carry possessive inflection in spoken form. The pronunciation is stable across American, British, and Australian varieties, though the surrounding vowel sounds and intonation can vary by accent.
Full pronunciation guide