As will be discussed in this chapter, there is an ever-growing body of clinical research evidence related to the field of occupational health and wellness. Part of this is due to the fact that we are in the midst of rapid global economic growth, with the attendant complex international and financial systems that produce an array of potentially significant problems, such as environmental and occupational hazards/diseases, worker safety and compensation issues, as well as psychosocial stress. The increase in clinical research in these areas has also produced numerous conceptual models/approaches to try to account for phenomena such as stress-illness relationships, individual differences in resiliency and productivity, and cross-cultural factors that affect occupational health and wellness. We will introduce the reader to some of these models in this chapter. Before doing so, a brief historical overview of events that have led to the development of this ever-expanding field will be provided.