The study investigated the academic engagement and achievement orientation as correlates of reading culture of in-school adolescents in Enugu State, Nigeria. Using correlational survey research design, the study made use of a population of 3469 senior secondary 11 (SS11) in-school adolescents. A purposive sampling and stratified random sampling techniques were used to draw a sample of 340 in-school adolescents. Four research questions and two null hypotheses tested at 0.05 level of significance guided the study. The three instruments used for data collection were in-school adolescents’ academic engagement scale (IAES), in-school adolescents’ achievement orientation scale (IAAOS) and in-school adolescents’ reading culture scale (IARCS). Research questions 1-3 were answered using means and standard deviation whereas research questions 4 and 5 were answered using Pearson r and R-square. The hypotheses were tested using analysis of variance (ANOVA) at 0.05 level of significance. It was found that in-school adolescents’ academic engagement and achievement orientation significantly related with their reading culture. Based on the findings of the study, it was recommended among others that, the government, school administrators and educators put concerted effort to encourage students to be mastery  oriented and academically engaged in order to prevent deleterious outcomes associated with poor reading culture since high academic engagement  and high achievement orientation relates with positive academic outcomes.