Internal marketing is an interdisciplinary concept in business that builds on different fields, such as marketing, human resource management, communications, and strategy. It has been widely used as an approach to strategically promote an organization’s mission, vision, and values to its internal stakeholders, that is, employees, to gain support and build morale. This entry aims to offer an overview of its theoretical foundations from multiple disciplines and its main managerial applications. In addition, changes in the internal marketing practice caused by COVID-19 pandemic are explored to highlight the importance for leadership to take a fresh perspective in the strategy and adapt it for the post pandemic world.