Douglas Engelbart with the guidance and assistance of Bill English invented the mouse in the year 1960’s which was patented on November 17, 1970. At the time he was developing the mouse he used to work at Stanford University. The mouse created by Douglas was actually referred as "X-Y Position Indicator for a Display System" and was first used with the Xerox Alto computer system in 1973.
Douglas later demonstrated the moving cursor in an alto computer. However, earlier the mouse at that didn't look the way it looks now.