Douglas Engelbart at the Stanford Research Institute invented the mouse in 1963 after extensive usability testing. He never received any royalties for it, as his patent ran out before it became widely used in personal computers.

Eleven years earlier, the Royal Canadian Navy had invented the trackball using a Canadian five-pin bowling ball as a user interface for their DATAR system.

Several other experimental pointing-devices developed for Engelbart's oN-Line System (NLS) exploited different body movements, for example, head-mounted devices attached to the chin or nose, but ultimately the mouse won out because of its simplicity and convenience.

The first mouse was a bulky device and used two gear-wheels perpendicular to each other: the rotation of each wheel translated into motion along one axis. Engelbart received patent US3541541 on November 17, 1970 for an "X-Y Position Indicator for a Display System".

At the time, Engelbart envisaged that users would hold the mouse continuously in one hand and type on a five-key chord keyset with the other. The concept was preceded in the 19th century by the telautograph, which also anticipated the fax machine.

Bill English, builder of Engelbart's original mouse, invented the so-called ball mouse in 1972 while working for Xerox PARC. The ball-mouse replaced the external wheels with a single ball that could rotate in any direction.It came as part of the hardware package of the Xerox Alto computer.

Perpendicular chopper wheels housed inside the mouse's body chopped beams of light on the way to light sensors, thus detecting in their turn the motion of the ball. This variant of the mouse resembled an inverted trackball and became the predominant form used with personal computers throughout the 1980s and 1990s.

The Xerox PARC group also settled on the modern technique of using both hands to type on a full-size keyboard and grabbing the mouse when required.