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

See also

• Series 3 (disambiguation)