An object movement control system, an object movement control method, a server, and a computer program that can update the positional information of an object in a virtual space at high speed by appropriately distributing processing loads. Client control units obtain information about the position of a first object in a virtual space and information about movement of the first object and detect other objects that exist in a virtual region that contains the first object, which has been moved. The distances between objects that exist in a virtual region are calculated, and only when the number of objects the distances to which are shorter than a predetermined threshold exceeds a predetermined number, information about the objects is sent to a server. The server assigns a collision determination client that performs collision determination to each pair of objects selected from the objects.