在电子技术（特别是数字电路）中，数据选择器（英语：multiplexer，简称：MUX），或称多路复用器，是一种可以从多个模拟或数字输入信号中选择一个信号进行输出的器件。 一个有 2 输入端的数据选择器有 n 个可选择的输入－输出线路，可以通过控制端来选择其中一个信号被选择作为输出。 数据选择器主要用于增加一定量的时间和带宽内的可以通过网络发送的数据量。

数据选择器使多个信号共享一个设备或资源，例如一个模拟数字转换器或一个传输线，而不必给每一个输入信号配备一个设备。

In electronics, a multiplexer (or mux) is a device that selects one of several analog or digital input signals and forwards the selected input into a single line. A multiplexer of 2 inputs has n select lines, which are used to select which input line to send to the output. Multiplexers are mainly used to increase the amount of data that can be sent over the network within a certain amount of time and bandwidth. A multiplexer is also called a data selector. Multiplexers can also be used to implement Boolean functions of multiple variables.