Sometimes — with care
A small bite of banana won’t hurt a cat — but cats can’t taste sweetness, gain nothing from fruit, and the sugar works against them. File under “harmless but pointless”.
Bananas aren’t toxic to cats, so the occasional curious lick is fine. But the cat digestive system is built for meat: fruit sugar contributes to weight gain and can nudge blood glucose the wrong way in pre-diabetic cats — a real concern since diabetes is common in indoor cats. Most cats sniff banana and walk away; the ones that do eat it are usually attracted to texture or your attention rather than taste, since cats lack sweet receptors entirely.
A fingernail-sized piece occasionally, if your cat genuinely wants it. Never banana bread (sugar, possible xylitol — toxic to pets) or banana chips (fried, sugared). Diabetic or overweight cats: none.
Cats prefer meat: a shred of plain chicken beats fruit every time.
This article is 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.