A movement control system is a movement control system of a moving body configured to be moved by a driving system. The movement control system includes a planner, a corrector, and a controller. The planner is configured to execute an update process of updating a control plan of the driving system in accordance with reference information including first external environment information regarding an external environment of the moving body. The corrector is configured to execute, at a second timing between a plurality of first timings at each of which the update process is executed, a correction process of correcting the control plan in accordance with second external environment information regarding the external environment of the moving body. The second external environment information is different from the first external environment information. The controller is configured to control the driving system in accordance with the control plan.