Agriculture is undergoing a new revolution. Technological advances allow drones to perform multiple tasks, including spraying crop protectants, spreading fertilizers, sowing seeds and surveying fields. Use of agricultural drones is growing extremely rapidly, particularly in Asia and Latin America, but has received little attention because it has happened so quickly. This revolution is significant because drones have the potential to enhance agricultural sustainability and reduce health risks by applying inputs more efficiently and safely than conventional methods. Drones also have the potential to raise agricultural productivity and farm incomes, overcome labor scarcity, and support rural livelihoods. But they create tradeoffs, including new environmental and social externalities, and dilemmas around technological sovereignty and data privacy. Prior academic literature on agricultural drones has been largely technical. We review prior literature and diverse non-academic secondary sources to track the extent and characteristics of global agricultural drone diffusion, providing estimates of numbers of agricultural drones in 10 major agricultural producer countries. We analyze drivers of drone diffusion, including technological innovation, falling costs, outsourcing services, and favorable policy environments, and explore emerging evidence of the impacts of drones on farm labor, agricultural efficiency, productivity, and profitability, and occupational health. The paper concludes by setting out an agenda for applied transdisciplinary research on the sustainability and food security impacts of agricultural drones.