Who reads and writes fan fiction—and why—has long been a central concern of fan studies. Indeed, many of the foundational works in the field of fan studies aim to answer this question. These early studies set a paradigm for our understanding of who makes up fan fiction–centered communities nearly thirty years ago; however, it is clear that the paradigm is now outdated. To my knowledge, there are no wide-scale academic studies of how fan fiction authors identify themselves in online profiles, authors' notes, and other self-descriptive texts, although some fans have produced statistics. Rather, our understandings of fan fiction–centered communities instead rest on our own embedded experiences as fans. While our experiences are valuable, recent work has made it clear that focusing solely on our embedded perspectives may exclude a number of voices, experiences, and viewpoints from scholarly work. This article presents the results of a qualitative study that examines how fan fiction authors described themselves in the paratexts of 1,939 Harry Potter fan fiction works posted to Archive of Our Own (AO3)—over 1 percent of the Harry Potter fan fiction posted to AO3 at the time of the study. It aims to indicate demographic trends within the Harry Potter fandom, identify groups of fans who may have been elided from fan studies' core discourse, discuss why who writes fan fiction matters, and uncover future areas of research concern.