Movement influences the distribution and abundance of populations. Knowledge of movement patterns is particularly useful for parameterising assessments and designing management strategies for exploited fish populations. Despite importance to fisheries, limited empirical evidence have portrayed adult tropical lethrinids as sedentary with small home ranges and as mobile predators that potentially migrate long distances. To distinguish the typical movement patterns of redthroat emperor (Lethrinus miniatus), horizontal and vertical activity space use and depth utilisation were investigated. Sixty individuals were monitored for up to 12 months using an acoustic telemetry network comprising three reefs in the Great Barrier Reef, Australia. Evidence supporting a mobile lifestyle includes broad-scale movement (~160km) of one individual, periods of non-detection and potential movement away from the reef edge at night. Yet most individuals displayed high site fidelity and moderate-sized horizontal activity spaces (~4km²) over a period of up to 12 months. Individuals inhabited a variety of depths with an absence of consistent trends based on time or size of individuals. Variation in movement among adult redthroat emperor indicates that while some individuals migrate over long distances, spatial closures that cover individual reefs (>4km²) could provide protection from fishing for the more resident proportion of the population.