This study deals with the influence of social commerce in changing the purchasing behavior of millennials in India, particularly that of social media platforms as drivers of purchasing behavior. The sudden emergence of social commerce has therefore made this generation-class important to business firms in their quest to use social networks for commercial success, since millennials are tech-savvy and active users of social media. The data for the research have been collected from 493 millennial consumers in India who use Instagram, Facebook, and TikTok to discover, evaluate, and purchase products. Using the data, through Structural Equation Modeling, the relationships of key dimensions of social commerce, that is, social sharing, user interaction, and community engagement, have been drawn upon to study the impact of millennials on decision-making. The findings from here have shown that social sharing and peer recommendations have a pivotal role in shaping millennials’ problem recognition and information search behaviors. User interactions in the form of reviews, comments, and social proofs drive the evaluation of alternatives, while community engagement nurtures trust and fortifies purchase decisions. Through this analysis, it is confirmed that the dimensions of social commerce positively impact millennial decision-making, with a rationale that the shopping experiences are turning out to be more personalized and interactive. With these findings, businesses and marketers understand clearly how they should refine their approach in using social commerce for millennial consumers in India. By realizing how social interactions and digital engagement make customers act, companies can know how to adjust their methods to breed greater trust among customers, increase customer engagement, and drive greater conversions through the use of social media.