STX
- Atari ST
- C0 and C1 control codes
- Case STX Steiger
- Gymnasium (Denmark)
- Henry E. Rohlsen Airport
- London Stock Exchange
- Mini-STX
- STX (sports manufacturer)
- STX Corporation
- STX Entertainment
- STX Europe
- Saxitoxin
- Seagate Technology
- Shiga toxin
- South Texas
- St Croix, U.S. Virgin Islands
- St Cross College, Oxford
- Streaming Transformations for XML
- Structured text
- Syntaxin