This research project examines the impact of social media marketing on the consumer buying behaviour of Marks and Spencer. It explores how social media platforms influence customer decisions and engagement, comparing it to traditional marketing methods. The study utilizes both primary and secondary research methods, including a focus group questionnaire and a literature review of academic journals and online articles. The findings reveal key factors that drive consumer behaviour in the context of social media marketing, highlighting the importance of engaging content, personalized messages, and customer relationship building. The project concludes with recommendations for Marks and Spencer to leverage social media effectively for long-term brand loyalty and profitability.