Better to avoid
Best avoided. A tiny scrap won’t poison a cat, but ham is far too salty and fatty for such a small animal, and processed meats aren’t a healthy treat.
Ham is cured, processed pork — very high in salt and fat relative to a cat’s tiny daily needs. Cats are sensitive to sodium, and the rich fat can upset the stomach or, in prone cats, contribute to pancreatitis. While cats are meat-eaters and the protein itself is not toxic, processed deli meats are a poor choice next to plain cooked meat, and the preservatives and seasonings add nothing good.
Not a recommended treat. A pea-sized scrap of lean ham on a rare occasion will not harm a healthy cat, but there is no reason to make a habit of it — choose plain cooked meat instead. Avoid entirely for cats with heart, kidney or weight issues.
Plain cooked chicken or turkey gives the meaty treat without the salt.
Related: Can cats eat chicken? · Can cats eat cheese? · Can dogs eat ham?
General information, not veterinary advice. If your pet has eaten something potentially harmful or shows symptoms, contact your vet or an emergency clinic immediately. Full disclaimer.