The 13 species of hornbills occurring in Indonesia have been studied to varying degrees, but a comprehensive identification of knowledge gaps is still lacking. We conducted a systematic review of the literature to identify the species and topics that require further investigation. We searched the literature using ScienceDirect, Google Scholar, Neliti, ResearchGate, and the Google search engine for all publications from 1970 to 2023. Publications were grouped under 15 conservation and ecological topics related to hornbills. Our review included 183 publications, comprising journal articles (56.3%), theses/dissertations (23.5%), conference papers (18.6%), and small portions of books and book sections (1.6%). Almost all the literature (72%) had been published after 2013, while the remaining (28%) was published before this period. The need for further studies across all research topics was identified for several species, including the Sumba Hornbill Rhyticeros everetti, Sulawesi Hornbill Rhabdotorrhinus exharratus, and Papuan Hornbill Rhyticeros plicatus. We also underscore the need for investigation into seed dispersal, ecotourism, and research methods across all hornbill species. Enhancing research and drawing public attention to Indonesia’s hornbills should increase their popularity and may serve to increase financial resources. This is the first systematic review of hornbill research for Indonesia and provides important information to determine future hornbill studies in the country.