ATK
- A.T. Kearney
- ATK (football club)
- ATK Thiokol
- ATK motorcycles
- Aboriginal traditional knowledge
- Accessibility Toolkit
- Alliant Techsystems
- America's Test Kitchen
- Andrew Project
- Arachidonyl trifluoromethyl ketone
- Arbetstidsförkortning
- Atomistix ToolKit
- Atqasuk Edward Burnell Sr. Memorial Airport
- Attack (disambiguation)
- Bruton's tyrosine kinase
- Kiribati Grand Order