ABSTRACT This article presents a comparative linguistic analysis of proper nouns in Uzbek and English, focusing on grammatical, morphological, syntactic, semantic, orthographic, and sociolinguistic distinctions. Drawing upon research in onomastics, anthroponymy, and contrastive linguistics, it explores how each language marks and utilizes proper nouns within grammar and discourse. The study reveals that while proper nouns share similar referential functions across both languages, Uzbek demonstrates greater morphological integration, whereas English relies heavily on capitalization and syntactic constraints. These findings contribute to cross-linguistic studies, language pedagogy, and computational linguistics by clarifying how naming systems encode cultural and grammatical differences.