This article is about TRIPOS, the operating system. For the name given to undergraduate degree subjects by Cambridge University, see Tripos.

TRIPOS (TRIvial Portable Operating System) is a computer operating system. Development started in 1976 at the Computer Laboratory of Cambridge University and it was headed by Dr. Martin Richards. The first version appeared in January 1978 and it originally ran on a PDP-11. Later it was ported to the Computer Automation LSI4 and the Data General Nova. Work on a Motorola 68000 version started in 1981 at the University of Bath. MetaComCo acquired the rights to the 68000 version and continued development until TRIPOS was chosen by Commodore Amiga in March 1985 to form part of an operating system for their new computer; it was also used at Cambridge as part of the Cambridge Distributed Computing System.

At the University of Cambridge, the term Tripos (, plural 'Triposes') refers to undergraduate examinations which qualify an undergraduate for a bachelor's degree. It also refers to a course taken by an undergraduate. For example, an undergraduate studying mathematics is said to be reading for the Mathematical Tripos, whilst a student of English literature is reading for the English Tripos.