Systems Application Architecture (SAA), introduced in 1987, is a set of standards for computer software developed by IBM. The SAA initiative was started in 1987 under the leadership of Earl Wheeler, the "Father of SAA". The intent was to implement SAA in IBM operating systems including MVS, OS/400 and OS/2. AIX—IBM's version of the UNIX operating system—was not a target of SAA, but does have interoperability with the SAA family.

SAA did not define new standards, but selected from among IBM's existing guidelines and software. IBM also purchased some third party software from developers such as Bachman Information Systems, Index Technology, Inc., and KnowledgeWare, Inc. These were intended to be implemented uniformly across all SAA compliant environments.

The standard was "designed to make application programs look and work in the same manner across the entire range of the company's personal computing systems, midrange processors and System/370 processors."

SAA was labeled "complex, obscure, and potentially difficult to learn."^: p.xi Under Lou Gerstner IBM later quietly discontinued use of the "SAA" umbrella. By 2001, SAA was being spoken of in the past tense. However many of the individual components of SAA are still in use as of 2014.