GTK is a cross-platform GUI widget software toolkit.
GTK may also refer to: __NOTOC__ Computing Group Temporal Key, in IEEE 802.11i-2004 wireless network security
Organisations GTK Rossiya, a Russian airline (founded 1992) Geological Survey of Finland, a government agency (, founded 1885)
Television shows GTK (TV series), Australia (ran 1969–1975) Ghost Trackers, Canada (ran 2005–2008)
See also gtk--, former name of gtkmm, a C++ interface for GTK