轨迹球（Trackball）是和鼠标等一样的计算机定点设备的一种。

和机械式鼠标一样，轨迹球通过读取可滚动的球滚动的方向和速度来定位。不同的是，鼠标是基座和球一起动，而轨迹球只是球在基座上滚动，基座相对桌面不动。

A trackball is a pointing device consisting of a ball held by a socket containing sensors to detect a rotation of the ball about two axes—like an upside-down mouse with an exposed protruding ball. The user rolls the ball with the thumb, fingers, or the palm of the hand to move a pointer.