Coconut — Food safety facts
Feed with care · Cats · full breakdown on the linked food page
Fresh flesh in small amounts is usually fine; coconut water is high in potassium and milk/oil are very fatty. Watch for upset stomach.
Short answer
Small amounts of coconut water are not toxic to cats, but it is high in potassium, which can be problematic. Coconut milk and coconut oil are very fatty and may cause an upset stomach. Watch your cat for vomiting, diarrhea, or lethargy after ingestion. If your cat drank a large amount or shows symptoms, call your vet or the ASPCA Animal Poison Control line at 888-426-4435.