In this research, we drew on a model of self-regulated learning (SRL) (Butler & Cartier, 2005; Cartier & Butler, 2004) to investigate student engagement in learning through reading (LTR) as situated in context. Our overarching goals were to enhance theoretical understanding about SRL as situated, identify patterns in self-regulated learning through reading (LTR) for secondary students within and across classrooms, and continue developing productive methodological strategies for investigating SRL and LTR. To those ends, we employed a mixed-methods design to find patterns within and across 31 classrooms at multiple levels of aggregation. Participants were 646 secondary students engaged in curriculum-based LTR activities. Findings were derived from two coupled assessments: A self-report questionnaire and a performance-based measure of LTR. We used frequency, factor analytic, and cluster analyses to create descriptive profiles of SRL (across emotion, motivation, cognition, and metacognition). Main findings were: (1) important mismatches between students’ self-reported LTR engagement and the demands of LTR activities; (2) four coherent profiles of LTR engagement (actively engaged; disengaged; high stress/actively inefficient; passive/inactively efficient), (3) moderate links between students’ self-reported LTR profiles and LTR performance; and (4) differences in SRL profiles that reflected individual-context interactions. We close by distilling implications for understanding, researching, and fostering SRL as situated within naturalistic settings.