Régisseur is a classical ballet term that is a title for someone who restages or rehearses a ballet company. Depending on the size of the ballet company, there may not be a specific title of a régisseur with all of the rehearsing or restaging left up to the ballet masters or mistresses.
A régisseur may also be known as a répétiteur. Either way, it signifies someone who will reteach the steps of a ballet and repeatedly rehearse the dancers of a ballet company. It should not be confused with a choreographer, who is someone who is actually creating a ballet and the sequence of steps, also known as choreography.