The aim of this research was to study the dynamics of fourth graders' perceived social support for schoolwork and to examine how this support contributes to their study engagement. Social support was hypothesised to be positively associated with higher levels of study engagement. Moreover, social support from teachers and guardians was hypothesised to be associated with social support for schoolwork among peers. Differences between genders were studied in relation to perceived social support and study engagement. Structural equation modelling was used to test the hypotheses with cross-sectional survey data from 2400 fourth grade students from Finland. They were 10 years of age on average. The results indicate that social support from teachers and among peers has stronger effects on study engagement compared to support from guardians. Moreover, it was found that social support from teachers and guardians is associated with the social support that students share among their peers. Girls were found to be more engaged in studying and to experience more social support from teachers and among peers compared to boys. The perceived social support from teachers was found to be partly determined by the class group to which the student belongs. These results suggest that by providing emotional and informational support for their students, teachers might be able to promote students' study engagement, as well as such peer interaction that further enhances the students' study engagement.