光通信是一种利用光来携带信息的通信技术，也称为远程光通信。不论利用电子仪器传收或以肉眼直接观察光都属于光通信。光通信技术最早可以回溯到数千年前。即1880年发明的光电话机是最早的光通信仪器。

光通信系统由发射器（transmitter）、频道（channel）、接收器（received）组成。发射器将信息编码成光信号；频道将信号发送至目的地；接收器将光信号重新转换成发送的信息。当通信系统的设备中不使用接收器时，也可以是借由人眼观察来解释信号，简单的信号如烽火、复杂的信号则如光编译的色码或闪光摩斯密码等。

Optical communication, also known as optical telecommunication, is communication at a distance using light to carry information. It can be performed visually or by using electronic devices. The earliest basic forms of optical communication date back several millennia, while the earliest electrical device created to do so was the photophone, invented in 1880.