Short answer: Yes.
Most guinea pigs love bananas and they are safe for guinea pigs to eat.
It is important to remember that you can only feed bananas to guinea pigs in moderation as they are very high in sugar content.
If a guinea pig were to eat too many bananas they will have stomach issues and be constipated.
Additionally guinea pigs can eat the banana skin and leaves as long as they are chopped up.
Most guinea pigs love bananas so it is a great option for them within moderation.