Cats can eat lettuce, but it should only be given in moderation. Lettuce is non-toxic to cats and can provide some hydration and small amounts of vitamins and fiber, but it offers little nutritional value since cats are obligate carnivores and require a meat-based diet to thrive. Lettuce can be a safe occasional treat, but it should not replace a commercial cat food diet. It is important to wash the lettuce thoroughly and cut it into small, manageable pieces before offering it to a cat. Different types of lettuce, such as iceberg, green leaf, romaine, and butter lettuce, are generally safe in small amounts, but too much may cause digestive issues like diarrhea.