Can cats and kittens drink milk? In summary, the quick answer is no..
After weaning, your kitten does not need milk in their diet. A kitten gets all the nutrients they need from their food if given a nutrient rich dry kibble food.
Cats don't need and have trouble digesting cow's milk in their diet, so it is better to avoid giving them milk. The milk from a cow is different than the milk they drink from their mother.
Cats and kittens lack the enzymes to break down milk from a cow. Milk that is more like what a cat produces is goat's milk. However, with that said, cats and kittens do not to be given milk. If you feel the need to give you cat milk, you would be better to give them a milk substitute product that is more like the milk produced by a cat.