XLR端子是影音器材中常见的端子，经常用于连接专业影音器材和麦克风。一般家用影音器材常使用RCA端子发送由前级放大器产生的Line level信号。TRS端子也在家用及电脑用的麦克风中应用到。

基于原生产者是James H. Cannon（加州洛杉矶Cannon电子公司创办人，该公司现为ITT 公司旗下），XLR端子常俗称为Cannon插头或Cannon端子。最初端子为"Cannon X"系列，之后的版本加入了弹簧锁（Latch）成为"Cannon XL"系列，接着在端子接触面以橡胶包着（Rubber），成为了其缩写XLR的来源。 XLR端子的针头基本上三个外，还可以有更大针头数。

The XLR connector is a style of electrical connector, primarily found on professional audio, video, and stage lighting equipment. The connectors are circular in design and have between 3 and 7 pins. They are most commonly associated with balanced audio interconnection, including AES3 digital audio, but are also used for lighting control, low-voltage power supplies, and other applications. XLR connectors are available from a number of manufacturers and are covered by an international standard for dimensions, IEC 61076-2-103. They are superficially similar to the older and smaller DIN connector range, but are not physically compatible with them.