Dehumanization—the tendency to perceive others as less than fully human—is a multifaceted concept that ranges from blatant denials of others’ humanity in intractable conflicts to the management of a big company consistently referring to their employees as “assets” or “resources,” purely emphasizing their instrumental qualities. In the current chapter, we aim to bring some order in this multitude, clearly defining and characterizing the concept of dehumanization, providing an overview of the different ways in which dehumanization has been measured, discussing its drives and triggers and the outcomes it predicts. We then discuss some controversies and critiques that have been raised toward the concept of dehumanization and respond how they can or have been tackled in the literature. In the end, we reflect on the future of this field of research and propose some future directions.