Country-of-origin (COO) influences consumer perceptions of brand authenticity by shaping beliefs related to heritage, craftsmanship, cultural legitimacy, and product expectations. With globalization blurring national identities and supply chains, COO has evolved from a simple labeling variable to a key determinant of brand authenticity and credibility. This study examines how COO effects differ across product categories and cultural contexts, using mixed-method research including a 1,032-respondent global survey, interviews with branding professionals, and consumer case analysis from diverse markets. The study finds that COO strongly influences premium, heritage-driven products such as luxury fashion, automobiles, food, and traditional crafts, while its impact declines for digital services and commoditized goods. A conceptual COO–Authenticity framework is proposed, outlining mechanisms through which origin cues shape purchase intentions.