Increases in data availability coupled with enhanced computational capacities are revolutionising conservation. But in the excitement over the opportunities afforded by new data, fewer researchers have questioned the justice implications of data use in conservation: how people and environments are represented through data, and how this could alter the distribution of benefits and harm from conservation actions. We propose a framework for understanding the justice dimensions of conservation data, comprising the five elements of data composition, data control, data access, data processing/use, and data consequences. We illustrate the need for such a framework using recent debates over global conservation mapping. Finally, we outline strategies for reducing the risk of data injustices in conservation and argue for more research into the justice implications of practicing conservation in an increasingly datafied world.