While Nash (2022) has highlighted the increase in online activities during the pandemic and the broader influence of social media influencers, there remains a scarcity of specialized studies on this topic. This research delves into the impact of Key Opinion Leader (KOL), with a focus on Chau Bui, a famous Vietnamese fashionista and actress, on the attitude towards products of Gen Z in Ho Chi Minh City. Drawing on the groundwork laid by Xu Xu & Stephen Pratt (2018), the study employs quantitative methods and online surveys analyzed through SmartPLS software. The findings reveal a robust correlation between the attractiveness and reputation of KOL, the product's alignment with the KOL, and their collective impact on customers trust and attitudes towards products in Vietnam. These results carry significant implications for marketing practitioners, consumer behavior researchers, and local businesses in both Ho Chi Minh City and Vietnam. The study concludes with insights, limitations, and recommendations for future research.