Stax can refer to:
- StAX, (Computer Programming) Streaming API for reading and writing XML in Java
- Stax Earspeakers, a Japanese brand of electrostatic earspeakers
- Stax Records, an American record company
- STAf eXecution engine (STAX), a service available with Software Testing Automation Framework
- Lay's Stax, a brand of potato snack chips sold by Lay's
- Stax Inc., a management consulting firm