Motivation is a key component of organizational life. It is one of the largest areas of research in I-O psychology, with over 183,000 journal articles and dissertations on the topic in the PsycINFO database for psychology alone. In this chapter, you will learn about key motivation theories and their applications at work. This chapter addresses what work motivation is; needs-based theories of work motivation; process-based theories of work motivation; application-based theories of work motivation; key legal and global issues surrounding work motivation; and the current issues and research around work motivation.