Cinnamon — Food safety facts
Feed with care · Cats · full breakdown on the linked food page
A pinch of powder is usually fine. Large amounts irritate the mouth and stomach and can lower blood sugar.
Short answer
A tiny accidental taste of cinnamon powder is unlikely to cause serious harm to a cat, but it should not be given intentionally. Cinnamon can irritate a cat's mouth, throat, and stomach, and larger amounts may even lower blood sugar. Watch your cat for signs like drooling, vomiting, or seeming unsteady on its feet over the next few hours. If you notice any of these symptoms or if your cat consumed more than a few licks, it's best to call your veterinarian for advice.