<p><it>Abstract</it>—This paper presents efficient algorithms that implement one-to-many, or multicast, communication in wormhole-routed torus networks. By exploiting the properties of the switching technology and the use of virtual channels, a minimum-time multicast algorithm is presented for <it>n</it>-dimensional torus networks that use deterministic, dimension-ordered routing of unicast messages. The algorithm can deliver a multicast message to <it>m</it> - 1 destinations in $<tmath>\lceil {\bf log_2} \, {\mbi m} \rceil</tmath>$ message-passing steps, while avoiding contention among the constituent unicast messages. Performance results of a simulation study on torus networks with up to 4096 nodes are also given.</p>