The present disclosure relates to a control device, a control method, and a mobile object that effectively use storage capacity while saving the storage capacity and efficiently plan a movement route by storing or forgetting (deleting) a past detailed map according to importance during autonomous movement. When a global route is set, by storing or forgetting (deleting) a detailed map according to the importance on the global route to plan a local route from a frequently used global route, it is possible to efficiently plan a local route by combining detailed maps stored in the past.