BT may stand for:

• Air Baltic (in the IATA code)
• Bacillus thuringiensis or Bt toxin, (a.k.a. Cry proteins) - a family of insecticidal toxins and the bacterium which produces them
• the title Baronet in the British honours system
• Banjo-Tooie - a 2000 Nintendo N64 video game; sequel to Banjo-Kazooie
• Bankers Trust - an international banking organisation
• Bhutan (ISO 3166-1 alpha-2 country code)
• Binary Terrain - a GIS DEM file format
• Bitstream Inc. - a bitmap font-only type foundry
• BitTorrent - an Internet file distribution system
• Bluetooth - a wireless personal area network standard
• Bodensee-Toggenburg-Bahn - a former Swiss railway company
• Brian Transeau - the electronic music artist (who records as "BT")
• British Telecom (officially, BT Group plc) - the privatised former state telecommunications company of the United Kingdom
• B.T. - a Danish tabloid newspaper
• BT-2, BT-5, BT-7, the Soviet fast tanks
• the Burton Taylor Theatre (known as "The BT")
• Business Times - newspapers in Singapore and Malaysia