CLK
- CLK-1 (disambiguation)
- CLK2
- CLK3 (disambiguation)
- Cadillac and Lake City Railway
- Calumet High School (Calumet, Michigan)
- Chek Lap Kok
- Clackmannanshire
- Clinton Regional Airport
- Clock House railway station
- Confederation of Labour of Kazakhstan
- David Rath
- Hong Kong International Airport
- Intel 8253
- List of cruisers of the United States Navy
- Mercedes-Benz CLK-Class
- Public Schools of Calumet-Laurium-Keweenaw