Peel the bananas and slice them into thin rounds, about 1/8-inch thick.
In a small bowl, mix the lemon juice and cinnamon. Toss banana slices until evenly coated.
Preheat the air fryer to 350°F (175°C) for 2–3 minutes.
Arrange banana slices in a single layer in the basket, avoiding overlap.
Air fry the Air Fryer Cinnamon Banana Chips for 8–10 minutes, flipping halfway through.
Transfer to a wire rack and cool completely to allow them to crisp up.