Celebrity endorsement is a widely employed strategy in FMCG marketing; however, the comparative efficacy of regional versus national endorsers on consumer behaviour remains insufficiently examined, particularly in tier-2 Indian cities. This study investigates how Gujarati regional celebrities and pan-India national celebrities differentially influence the purchasing decisions of Generation Z (Gen Z) consumers in Rajkot. Grounded in Cultural Congruence Theory and the Elaboration Likelihood Model (ELM), the research proposes that shared cultural proximity amplifies message acceptance and purchase intent. A mixed-methods design was adopted: quantitative data from 300 Gen Z respondents (aged 18–26) were analysed via MANOVA and structural equation modelling, complemented by two focus group discussions. The results establish that regional endorsements yield markedly higher cultural congruence, emotional resonance, and purchase intention for most FMCG categories, whereas national celebrities sustain an advantage in brand prestige perception. Gender and product category emerge as significant moderators. The study contributes novel empirical evidence from a Gujarati urban context and offers practical guidance for FMCG marketers pursuing high-impact, cost-efficient endorsement strategies in tier-2 markets.