Olives contain healthy fats and some vitamins that can be beneficial in very small amounts.
Risks
Olives are often high in salt, which can be harmful to cats.
Additionally, the pits can be a choking hazard.
Suggestions
If you decide to give your cat an olive, ensure it is plain and unsalted.
Remove the pit to avoid choking hazards and only offer a small amount as an occasional treat.
Note: even if labeled as safe, any food can potentially cause allergies. When introducing a new food, please feed a small amount and observe your cat for any allergic reactions.