The notion of resilience originated in the ecology literature in the modern or post-World War II era. Even so, this term has now found widespread use in the social sciences in general and in regional science in particular. Although this expansion in the use of resilience is welcome, it is important to recognize that there is some ambiguity and confusion in the extant regional science literature about foundational issues and hence also about the nature of policy when resilience is a factor to contend with. Given this state of affairs, in this chapter, we provide a detailed discussion of three foundational and two policy related issues concerning the use of resilience in regional science. The three foundational issues are about definitions, whether resilience is a process, and whether resilience is always a good thing. The two policy issues concern multiple stable states and the connection between the twin notions of resilience and sustainability. The chapter concludes with some retrospective and prospective remarks.