Due to COVID-19, the beauty industry experienced a significant decline in sales. Research has shown that the impact of Kim Jisoo as a brand ambassador of Dior Beauty has significantly boosted sales and brand worth. This phenomenon has led to research that explores the impact of social media marketing (SMM), specifically through Instagram, and the role of brand ambassadors, focusing on Jisoo’s collaboration with Dior Beauty on-brand image enhancement in the luxury brand sector. The study uses the social influence theory, signaling theory and the Stimulus – Organism – Response (SOR) theory. The study also employs quantitative research design, using a structured questionnaire distributed to Instagram users exposed to Dior Beauty and Jisoo on the platform to assess the effectiveness of social media marketing and brand ambassador strategies in marketing luxury brands, implementing nonprobability sampling, specifically purposive sampling. The data obtained is processed using Smart PLS 4 software to be analyzed. Findings shows that Social Media Marketing and Brand Ambassador have a significantly positive effect on Dior Beauty’s Brand Image on Instagram. The managerial implications highlight the importance to improve social media marketing as constructs – Entertainment, Customization, Interaction, E-WOM, and Trendiness has shown to have not performed maximumly. Construct of Brand Ambassador such as Visibility, Credibility, Attraction, and Power also shown to need further improvements as they lie on Quadrant II (Concentrate Here).