In everyday speech referring to someone as an engineer signals their having an engineering identity – marking that person as belonging to a group of people who practice engineering. In the popular imagination, engineers mistakenly tend to be considered (at least in the United States) as socially inept sorts who are fascinated with gadgets and fixing things, more practical than scientists, and somehow brainier than technicians. As such, though “engineer” provides vernacular shorthand for everyday conversation, research on engineering identity unpacks nuanced ways of being engineers, as well as delineates how being an engineer relates to doing engineering. Engineers’ identification with their profession can be critical for persistence, both as a student and then as a professional (see Chapter 16 by Lichtenstein, Chen, Smith, & Maldonado, this volume). Studies show that a lack of identification with, and by, engineering often motivates students to migrate out of engineering into other majors and can be a barrier for students in other majors to move into engineering (Seymour & Hewitt, 1997; Tonso, 2006a; see also Chapter 15 by Sheppard, Gilmartin, Brunhaver, & Antonio, this volume). In fact, identity and learning prove interconnected, as delineated by several scholars in the situated learning tradition from cultural anthropology (Greeno, 2006; Johri & Olds, 2011; Lave & Wenger, 1991; Tonso, 1997; Wenger, 1998). Within this tradition, learning is itself conceptualized as a change in identity that comes with participation. As learners move from novices to mature practitioners, they likewise shift from peripheral participation to fuller participation; they undergo identity transformations and their identifying with a community of practice becomes a central part of the learning that takes place. According to this perspective, students learn as they engage in meaningful activities, involved not only in the learning of content, but also in learning how to put content learning into perspective, gain conceptual understanding, and become part of a community. But, though self-identification grounds an emerging engineering identity, as Tonso (1999, 2006a) demonstrated, being identified by the community as belonging also proves crucial, and lack of identification can interfere with belonging for some with well-regarded competencies.