Preheat the air fryer to 350°F.
Prep two shallow bowls for dredging. Add flour into one of the bowls and beat the eggs in the other bowl.
Cut off the ends of the onion and peel off its skin. Slice it into thick rings, separating each individual onion ring.
Dip the rings into the egg mixture, coating both sides.
Dredge the egg-coated onion ring in flour.
Drizzle the onion rings with olive oil and place them in the air fryer. Cook for 12-15 minutes, flipping the rings halfway through the cooking time.
Remove the onion rings from the air fryer and place them on tray for serving.