BTK

BTK may refer to:

Biology

Bacillus thuringiensis subspecies kurstaki, a subspecies of a Gram-positive, soil-dwelling bacterium, commonly used as a biological pesticide or insecticide
Bruton's tyrosine kinase, a protein whose mutation is associated with X-linked agammaglobulinemia

The Bulgarian Telecommunications Company, abbreviated as БТК in Cyrillic and sometimes transliterated as BTK
Bilgi Teknolojileri ve İletişim Kurumu (aka Information And Communication Technologies Authority), Turkish Info&com regulatory body

Birth Thru Knowledge, a Canadian hip-hop/rock band best known for the 1998 single "Peppyrock"
"Bind Torture Kill", a song by the band Suffocation on its album Suffocation.
"Bind, Torture, Kill" is a song by the band Suicide Commando on its album Bind, Torture, Kill.

Baku-Tbilisi-Kars Railway
Dennis Rader, a serial killer known as the "BTK killer"
The Kaiser-Fleetwings XBTK, a dive and torpedo bomber developed for the United States Navy from 1944 to 1946
Pillars of Truth (Boutokaan Te Koaua), a political party in Kiribati
Blonder Tinkham Klapwijk, the 3 physicists who wrote a theory to describe electrical transport across an interface between a non-superconducting metal and a superconducting one, based on the concept of Andreev reflection.