Adolescents' in-school identities, out-of-school identities, and literacy practices are intertwined and connected. This research project aimed to explore the development of adolescent identities and out-of-school literacy practices in students' English Language Arts classes. As a high school teacher and administrator, the researcher adopted a constructivist approach and conducted a cross-case analysis of six ninth-grade students from classroom observations, interviews, and an identity-centered word sort activity created for the study. The researcher's analyses revealed the students' out-of-school identities, preferred literacy practices, and personal affinities were underrepresented in their English Language Arts class. The key findings in the study support a multi-faceted definition of literacy for adolescents and that identity-centered approaches in classrooms may be conducive to increasing their interest in English Language Arts skills and content. These findings support the argument that adolescents' in-school identities and out-of-school identities need to be incorporated into classroom literacy practices. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]