Education researchers and practitioners have been exploring for years the key factors impacting children's academic engagement. Still, relatively little is known about the role of children's social cognition in their academic engagement. Accordingly, the current study focuses on the potential indirect associations between young children's social information processing patterns (SIP) and their academic engagement through their social behaviors in class, specifically their prosocial and problem behaviors, and following by the quality of their relationship with their main kindergarten teacher. The study examines these indirect effects in one dual-pathway model which includes both a pathway from children's competent SIP patterns to higher levels of academic engagement and from children's aggressive SIP patterns to lower levels of academic engagement. The sample included 300 kindergarten children (151 girls; Mage = 68.76 months). Results showed that competent SIP patterns were positively linked to children's academic engagement, which encompasses both their academic self-perceptions and their attitudes toward learning, via children's prosocial behaviors in class and subsequently teacher-child relational closeness. In addition, aggressive SIP patterns were negatively linked to the kindergarteners' attitudes toward learning via the children's problem behaviors in class and subsequently teacher-child relational conflict. Results have implications for both research and practice in the understanding of the influence of social cognition, behavior, and social relationships on academic engagement for young learners.