星型拓扑（英文：Star Topology）是指网络中的各节点设备通过一个网络集中设备（如集线器HUB或者交换机Switch）连接在一起，各节点呈星状分布的网络连接方式。这种拓扑结构主要应用于IEEE 802.2、IEEE 802.3标准的以太网中。

Star networks are one of the most common computer network topologies. In its simplest form, a star network consists of one central switch, hub or computer, which acts as a conduit to transmit messages. This consists of a central node, to which all other nodes are connected; this central node provides a common connection point for all nodes through a hub. In star topology, every node (computer workstation or any other peripheral) is connected to a central node called a hub or switch. The switch is the server and the peripherals are the clients. A star network is an implementation of a Spoke–hub distribution paradigm in computer networks. Thus, the hub and leaf nodes, and the transmission lines between them, form a graph with the topology of a star. If the central node is passive, the originating node must be able to tolerate the reception of an echo of its own transmission, delayed by the two-way transmission time (i.e. to and from the central node) plus any delay generated in the central node. An active star network has an active central node that usually has the means to prevent echo-related problems.