In this article, we conduct an integrative and rigorous review of theory and research on education in emergencies programs and interventions as international agencies implement them in areas of armed conflict. We ask several questions. How did this subfield emerge and what are the key conceptual frameworks that shape it today? How do education in emergencies programs affect access, learning, and protection in conflict-affected contexts? To answer these questions, we identify the conceptual frameworks and theoretical advances that have occurred since the inception of the field in the mid-1990s. We review the theories that frame the relationship between education and conflict as well as empirical research that tests assumptions that underpin this relationship. Finally, we assess what we know to date about "what works" in education in emergencies based on intervention research. We find that with regard to access, diminished or inequitable access to education drives conflict; conflict reduces boys' and girls' access to education differently; and decreased distance to primary school increases enrollment and attendance significantly for boys and even more so for girls. With regard to learning, education content likely contributes to or mitigates conflict, although the mechanisms through which it does so remain underspecified; and peace education programs show promise in changing attitudes and behaviors toward members of those perceived as the "other," at least in the short term. Finally, providing children living in emergency and postemergency situations with structured, meaningful, and creative activities in a school setting or in informal learning spaces improves their emotional and behavioral well-being.