This report provides an in-depth analysis of management and leadership functions within Marks & Spencer (M&S). It defines the roles of managers and leaders, comparing their characteristics with specific reference to M&S. The report explores the differences between managerial functions and leadership roles, applying various management theories such as transformational leadership and Fayol's Functions of Management. Examples from M&S illustrate how leadership roles and managerial functions are applied in different situations. Furthermore, it assesses the strengths and weaknesses of situational, systems, and contingency leadership theories, alongside the Chaos Theory of Management and Participative Management Theory, in the context of supporting growth and sustainable performance at M&S. The report concludes by highlighting the importance of adapting management and leadership approaches to achieve organizational goals.