激光测距仪是一种利用激光束测定距离的仪器。

其基本原理是，向待测距的物体发射激光脉冲并开始计时，接收到反射光时停止计时。这段时间即可以转换为激光器与目标之间的距离。

激光测距仪也可以发射多次激光脉冲，通过多普勒效应来确定物体是在远离还是在接近光源。

由于光速太快，这种仪器在测量近距离时并不准确。在需要小于毫米级别的高精度测距时，三角测量法更为适宜。

A laser rangefinder is a rangefinder which uses a laser beam to determine the distance to an object. The most common form of laser rangefinder operates on the time of flight principle by sending a laser pulse in a narrow beam towards the object and measuring the time taken by the pulse to be reflected off the target and returned to the sender. Due to the high speed of light, this technique is not appropriate for high precision sub-millimeter measurements, where triangulation and other techniques are often used.