CLK can stand for:
- Confederation of Labour of Kazakhstan
- Mercedes-Benz CLK-Class
- Chek Lap Kok - the island where the Hong Kong International Airport is based
- Ceska Lekarska Komora - Czech doctor's organization
- Cadillac and Lake City Railway
- See also
- CLK1, CLK2, genes
- CLK3, airport code for Lucknow Airpark