This dissertation investigates the phenomenon of mission drift with a focus on identifying its sources and mitigation strategies. Mission drift – a deviation of social enterprises from their original social mission and identity in pursuit of financial sustainability - is a significant challenge, particularly for younger organizations. Existing research provides a strong foundation, but there is a need for fresh perspectives on how mission drift occurs in various contexts, such as market, culture, and societal complexities, and how it is experienced by product-oriented versus serviceoriented enterprises. Most studies have focused on older, more established organizations, leaving a gap in understanding mission drift in newer social enterprises. This research explores this gap by examining two key questions: the factors contributing to mission drift and the strategies implemented to mitigate or address this risk. Employing qualitative methods, including semistructured interviews with founders of UK-based social enterprises, yields nuanced findings based on participants' backgrounds and experiences. By applying institutional theory and organizational theory, this dissertation identifies novel factors that lead to mission drift and new strategies for maintaining mission integrity. This dissertation offers new theoretical and practical insights, advancing the field of social entrepreneurship by providing fresh insights and strategies to counteract mission drift