Ext, ext or EXT may refer to:

  • Ext functor, used in the mathematical field of homological algebra
  • Extended file system, a file system created for Linux; see also ext2, ext3 and ext4
  • Ext (JavaScript library), a programming library used to build interactive web applications
  • Exeter International Airport (IATA airport code), in Devon, England
  • Extratropical cyclone, a mid-latitude cyclone
  • Extremaduran language (ISO language code), spoken in Spain
  • Extremeroller, a former roller coaster at Worlds of Fun, Kansas City, Missouri
  • Cadillac Escalade EXT, a pickup truck