Yes — bananas are soft, digestible, rich in potassium, and a reliable favorite for almost every parrot species.
What it means for African greys
There's nothing specific to a african grey that changes the verdict on banana — it's treated the same as for parrots generally. Greys can take a larger portion than small parrots.
The full picture on banana
Banana is one of the gentlest fruits you can offer: easy on the digestive system, free of seeds or pits to worry about, and packed with potassium and vitamin B6. Its soft texture suits everything from a weaning chick to an elderly macaw.
Peel and offer chunks or rounds; mash for young or unwell birds.
High in sugar as fruits go — a few bites, not a whole banana.
Plain dried banana works for foraging toys; skip fried 'banana chips'.