Look up OS X in Wiktionary, the free dictionary.
OS X is a former name of Apple's operating system macOS.
OSX or OS X may also refer to:
- DC/OSx, 1980s-era Unix operating system by Pyramid Technology
- Old Saxon (ISO 639-3 language code), an early form of Low German
- OSX, a Brazilian shipbuilding company, part of the EBX Group
- OS-X series, a series of sounding rockets built by OneSpace
- Xalapa Symphony Orchestra, from an acronym for its Spanish name Orquesta Sinfónica de Xalapa