This chapter introduces the transdisciplinary research movement of critical discourse analysis (CDA) beginning with its definition and recent examples of CDA work. In addition, approaches to CDA such as the dialectical relational (Fairclough), socio-cognitive (van Dijk), discourse historical (Wodak), social actors (van Leeuwen), and Foucauldian dispositive analysis (Jӓger and Maier) are outlined, as well as the complex relation of CDA to pragmatics. Next, the chapter provides a brief mention of the extensive critique of CDA, the creation of critical discourse studies (CDS), and new trends in CDA, including positive discourse analysis (PDA), CDA with multimodality, CDA and cognitive linguistics, critical applied linguistics, and other areas (rhetoric, education, anthropology/ethnography, sociolinguistics, culture, feminism/gender, and corpus studies). It ends with new directions aiming towards social action for social justice.