STX may refer to:

Businesses

• Seagate Technology, a hard drive manufacturer with stock symbol STX
• STX (sports manufacturer), a sports manufacturer based in Baltimore, Maryland
• STX Corporation (System Technology Excellence), a Korea-based holding company
• STX Entertainment, a Los Angeles-based motion picture production and distribution company
• STX Europe, a ship builder

Chemistry

• Saxitoxin, a neurotoxin found in marine dinoflagellates
• Shiga toxin
• Syntaxin, a membrane integrated Q-SNARE protein participating in exocytosis

Computing

• A secure private telephone network used by London Stock Exchange affiliated firms and professionals
• PASTI raw disk image format for the Atari ST
• Start of Text, a control code in the C0 control code set
• Socket Technology EXtended, the Mini-STX computer form factor
• Streaming Transformations for XML, an XML transformation language
• Structured text, a plaintext markup language

Places

• Henry E. Rohlsen Airport (IATA code: STX), an airport on St. Croix, U.S. Virgin Islands
• South Texas
• St Croix, U.S. Virgin Islands
• St Cross College, Oxford

Other uses

• Case STX Steiger, a tractorline built by Case IH
• Star Trek: Nemesis, the 10th film in the Star Trek film franchise (Star Trek X)
• Almen studentereksamen, an examination used in Denmark for the secondary school called gymnasium