The layered transition metal dichalcogenides have attracted considerable interest for their unique electronic and optical properties. While the monolayer MoS₂ exhibits a direct bandgap, the multilayer MoS₂ is an indirect bandgap semiconductor and generally optically inactive. Here we report electric-field-induced strong electroluminescence in multilayer MoS₂. We show that GaN–Al₂O₃–MoS₂ and GaN–Al₂O₃–MoS₂–Al₂O₃-graphene vertical heterojunctions can be created with excellent rectification behaviour. Electroluminescence studies demonstrate prominent direct bandgap excitonic emission in multilayer MoS₂ over the entire vertical junction area. Importantly, the electroluminescence efficiency observed in multilayer MoS₂ is comparable to or higher than that in monolayers. This strong electroluminescence can be attributed to electric-field-induced carrier redistribution from the lowest energy points (indirect bandgap) to higher energy points (direct bandgap) in k-space. The electric-field-induced electroluminescence is general for other layered materials including WSe₂ and can open up a new pathway towards transition metal dichalcogenide-based optoelectronic devices.