Discourse Analysis (DA) refers to the systematic study of both written text and talk and its role in constructing social reality. DA is much more than a qualitative methodology: it is theoretically and epistemologically informed by social constructionism and has been central to challenging the dominance of cognitive and perceptual theoretical models in psychology. Currently, there is a diverse range of approaches to analysing discourse that differ markedly from each other, so DA should not be treated as a unified approach. This chapter will consider this tradition of research, its intellectual influences, its historical trajectory in psychology and the radical critique it has directed toward many of its taken-for-granted concepts. It will also outline some core principles in DA and demonstrate how they are examined in the analysis of discourse.