Mint leaves — Food safety facts
Feed with care · Cats · full breakdown on the linked food page
A few fresh leaves are harmless. Concentrated mint oils or a lot of leaves can irritate the stomach.
Short answer
A few fresh mint leaves are generally safe for a cat if given in moderation. Mint is not toxic, but large amounts or concentrated oils can irritate the stomach. Watch for signs like vomiting, diarrhea, or loss of appetite. If any of those appear, give your vet a call.