The Design Laboratory (D-Lab) at the Harvard T.H. Chan School of Public explores how design and public health can work together on the well-being of people, organizations, and the natural environment. It conducts research and develops education and translation programs using an advanced set of design frameworks and methods that are pliant, flexible, and adaptable to fit the uncertainty and volatility of today's complex challenges. This way of working integrates considerations from systems and patterns in daily life with a particular focus on situations where data about the behavior of people and organizations are incomplete and changes quickly. The D-Lab has two overall goals: expand public health knowledge towards the complexity of human and organizational behavior and formalize core aspects of design knowledge, helping the field make progress in a more structured manner. Bringing design to public health will not generate a substitute for current public health practices; rather, it complements the ways the field works to solve seemingly intractable problems at the intersection of well-being and behavior.