The presented study’s objective is to identify the mediating role of conscious self-regulation in the relationship between the components of school engagement and the academic performance of students of different grades. We used the following methods: the Russian version of the questionnaire "Multidimensional School Enga gement Scale" (Wang et al., 2019b; Fomina, Morosanova, 2020); V.I. Moro sanova's questionnaire "The Self-Regu la tion Profile of Learning Activity Ques tion naire (SRPLAQ)" (Morosanova, Bon darenko, 2017). The study analyzes the data obtained from a sample of students in grades 5–11 (N = 1127). New significant results were obtained on the relationship between conscious self-regulation and school engagement, as well as the specifics of their joint contribution to the academic performance of students of different ages. It is shown that conscious self-regulation acts not only as a resource for academic success but also as a factor mediating the impact of school engagement (its general level and individual components) on academic performance. The analysis showed the mediating effects of conscious self-regulation related to cognitive, emotional, behavioral and social components of school engagement. The analysis of moderated mediation revealed significant moderating effects of the age factor (school grade) on the relationship between self-regulation, school engagement and academic performance. The most pronounced mediating effects were found in grades 7, 10, 11. The obtained results are discussed in the context of the problem of conscious self-regulation development, the dynamics of school engagement and academic motivation in different periods of education, and the possibility of developing practical programs aimed at maintaining school engagement and academic performance of students.