Individuals are thought to have unique characteristics, to be coherently embodied, and to be agentive in contemporary Western society. Identity is associated with the individual's understanding of the self, a person's self‐presentations, other people's view of the individual, state and cultural conceptions of the individual, and technological readings and renderings of the person. The internet has confirmed and challenged these cultural conceptions of the unique, authentic, and unchanging individual because people produce and engage with versions of the online self. Online identities can be defined as constructed personas, which are maintained by system participants and technologies. Thus, people's online practices can support stable notions of the individual and their behaviors can have more destabilizing implications for these conceptions of the coherent person and body when they do not distinguish between the self and companies, products, technologies, and other individuals. Online identities can be associated with or distinguished from aspects of people's everyday identities, including their gender, race, sexuality, age, and class. While online identities were once associated with opportunities to employ the internet anonymously, social networking and the economic value of people's data have resulted in increased forms of verification and tracking. This entry details varied aspects of online identities, including the ways people are constituted through sign‐up forms, avatars, the design and interface features of online sites, emoticons, and algorithms.