This dissertation is a virtual ethnography examining the ways in which trans and nonbinary individuals construct, discuss, and "do" gender through the medium of online social networking services, specifically through Twitter. As being trans involves contesting the gender previously assigned to the individual—with the body providing the primary basis for this initial assignment—and as social networking services provide an interactional environment where the body can be curated or concealed entirely, these services provide a fruitful case study into how the construction and enactment of gender manifests itself outside the context of the body. This dissertation is comprised of three substantive sections, covering how the trans community constructs and justifies a definition of gender and how this definition both conflicts and aligns with definitions proposed by anti-trans groups, how Twitter's affordances for both personal expression and collective organization are utilized to foster within-community solidarity and how structural tensions within these affordances also work to undermine it, and the role that pervasive anti-trans opposition plays on influencing both the structural and emotional composition of the online trans community. The dissertation finds that the definition of gender employed by the online trans community—which prioritizes self-declaration—is mirrored within the community's structure, with Twitter's affordances utilized to cultivate group boundaries and a group style centered around a logic of inclusion. Yet the same structures which help to foster solidarity between members of the trans community also work against it: Twitter's privileging of messages which have the potential for wide dispersion comes at the expense of excluding more peripheral members, and increased immersion into the field exposes individuals to anti-trans hostility occurring on a global scale in a way that is difficult to emotionally separate oneself from.