A mechanism is provided for priority-based power capping. A power management controller identifies a set of priorities for a set of partitions of the data processing system. The power management controller determines whether a measured power of the data processing system exceeds a power cap for the data processing system. Responsive to the measured power exceeding the power cap, the power management controller sends a set of commands to a set of component actuators to adjust one or more of a set of operation parameters for a set of components associated with the set of partitions using the set of priorities. The set of component actuators adjust the one or more of the set of operational parameters associated with the set of component in order to reduce a power consumption of the data processing system.