System 3

System 3, System/3 or System III may refer to:

Computing and electronics

 * Acorn System 3, a home computer produced by Acorn Computers from 1980
 * Cromemco System Three, a home computer produced by Cromemco from 1978
 * IBM System/3, a low-end business computer manufactured between 1969 and 1985
 * IBM System/3X, a line of general business midrange computers manufactured from 1975
 * Operating System/3, operating system made by UNIVAC
 * System Software 3, operating system made by Apple
 * System 3 (software company), a software development firm
 * UNIX System III, operating system released by AT&T
 * Zenith System 3, a line of television models by Zenith Electronics

Other

 * System 3 in Trilogy, album by Criss Angel and Klay Scott
 * System 3 FC, a football club in St Vincent and the Grenadines
 * STS-3 (Space Transportation System-3), the Space Shuttle mission