Yes, cats can eat cantaloupe (cat-aloupe?), but only in extreme moderation.
Cantaloupe does provide several health benefits. It's a good source of antioxidants like vitamin C, beta carotene, and phytonutrients that help to fight free radicals within the body. It's also low in calories and high in water content, which aids hydration and makes it an appropriate snack for warm weather.
That being said, cantaloupe should not be a significant portion of your cat's diet. You should never feed them cantaloupe unless you do so infrequently, and in very small quantities. For cats, overeating melons like cantaloupe can lead to digestive problems like diarrhea due the fruit's high sugar and fiber content.
Cats are obligate carnivores, which means they need to get most of their nutrients from meat. Not only is there a limit to which fruit-based nutrients can benefit them — cats can't even taste sweetness the way humans dogs can, which means they can only derive so much benefit (and enjoyment) from eating a sugary fruit like cantaloupe.
As always, before introducing a new food item into your pet's diet, consult with your veterinarian first. If your cat eats cantaloupe (or any food) and is showing signs of illness such as lethargy, diarrhea, or vomiting, reach out to your veterinarian immediately. If they require veterinary care related to eating any unsafe foods, pet insurance can help cover the cost of treatment.