通信兵（英语：signaller）是一个兵种，职责为处理军事通信（military communications）。各个军种都辖有此兵种。

军事通信手段有电报、电话、卫星通信、野战通信网、步话机、机动通信（乘车或徒步）等。通信兵由野战通信、固定台站通信、通信工程和军邮勤务等专业部（分）队组成；

步兵师属的通信营，典型包括两个无线连、一个（有线）通信连、一个（无线）接力连、一个（有线）架设连.

美国陆军通信兵（英语：United States Army Signal Corps），由Albert J. Myer少校（Major）于1860年创立。

A signaller or signaleer in the armed forces is a specialist soldier, seaman or airman responsible for military communications. Signallers, aka Combat Signallers or signalmen or women, are commonly employed as radio or telephone operators, relaying messages for field commanders at the front line (Army units, Ships or Aircraft), through a chain of command which includes Field headquarters and ultimately governments and non government organisations. Messages are transmitted and received via a communications infrastructure comprising fixed and mobile installations.