Educational researchers have provided evidence that students who see themselves as valued members of their university (institutional belongingness) tend to have higher academic performance than students with a weaker sense of institutional belongingness. The current research draws on social cognitive theory to inspect two mechanisms that might explain this correlation: social self-efficacy and metacognitive strategies. We tested a double-mediation model with a large sample of students (n = 1,480) from one higher education institution in New Zealand. Using structural equation modeling, social self-efficacy and metacognitive strategies were meaningful contributors to the relation between institutional belongingness and Grade Point Average (GPA). Our discussion focuses on how universities can design strategies that promote belongingness and, in turn, improve how students interact, learn, and perform.