This chapter conceptually examines the relationship between social media and sustainable consumption from a behavioral marketing perspective. The growing gap between consumers’ attitudes toward eco-friendly products and their actual purchasing behavior remains a central concern in academic inquiry. The influence of social media on sustainable consumption is analyzed across three dimensions: awareness formation, social influence and norms, and behavioral guidance. Within the behavioral marketing framework, the chapter emphasizes that psychological, emotional, and social factors play a decisive role in consumer decision-making, and discusses why environmental sensitivity does not always translate into purchasing behavior. This attitude–behavior gap is explained through variables such as price perception, ingrained habits, lack of trust, and digital visibility. The chapter aims to provide a conceptual framework for social media-driven sustainable marketing practices and to lay the groundwork for future empirical research.