Social-media has developed into a potent advertising tool in the current digital age, enabling businesses to engage with their customers directly with influence her opinions. Building and improving brand image has been greatly aided by social media advertising in recent years. As more people utilize social media, brands are adopting these channels more frequently to engage with their target markets. The well-known cosmetics company Maquillage is the subject of this study, which looks at how social media advertising influences consumer behaviour and brand perception. With a case study methodology, the study examines how Maquillage marketing campaigns on social media sites like Facebook, YouTube, and Instagram affect consumer sentiment, purchasing patterns, and brand perception in general. By integrating qualitative and quantitative methods, such as content analysis of Maquillage social media campaigns and survey responses from its target audience, this study takes a hybrid-method approach. The results indicate that influencer collaborations, interactive ads, and aesthetically appealing content are crucial for raising consumer engagement, establishing brand trust, and influencing purchase intention. Furthermore, promoting Maquillage brand on several social media channels with authentic and consistent messaging enhances the company's reputation. In all, sixty participants in the extensive quantitative analysis were between the ages 18 to 40. Cosmetic brands looking to use social media for strategic marketing and brand development will benefit greatly from the research's insightful conclusions.