- ZK stands for New Zealand (aircraft registration prefix)
- ZK stands for Czech Republic (country code)
- ZK stands for Zentralkomitee (German: Communist Party Administration)
- ZK stands for Zur Kenntnisnahme (German: For Information)
- ZK stands for Zero-Knowledge (cryptography)
- ZK stands for Zambian Kwacha (national currency)
- ZK stands for Barrage Balloon (Navy Symbol)
- ZK stands for Kite Balloon Squadron (US Navy)
- ZK stands for Zillion Kajillion Rhymes (Eccentric Software)
- ZK stands for Zaklyuchennyi (prisoner in former Soviet Union)
ZK