This chapter establishes the conceptual framework for understanding the ‘resilience of planning’ as a critical lens for examining planning approaches. It begins by delineating various perspectives on resilience thinking, with particular emphasis on evolutionary resilience and its transformative impact on planning theory and practice. Through a historical analysis of planning thought evolution, the chapter reveals how resilience concepts have been implicitly embedded within diverse planning paradigms from the mid-twentieth century to the present. The analysis traces how planning theory has progressively moved from equilibrium-focused approaches towards acknowledging complexity, uncertainty and socio-spatial interdependence. The chapter culminates by examining adaptive planning as an approach that most comprehensively addresses the core attributes of evolutionary resilience—particularly its recognition of fundamental uncertainty and the relational nature of space and time. By establishing the theoretical foundations of planning resilience, this chapter provides the analytical framework for subsequent empirical investigations of a planning system’s transformations across distinctive historical and institutional contexts.