Wash the asparagus thoroughly and pat it dry with paper towels.
Snap or trim off about ½ to 1 inch from the woody ends of each spear.
Preheat your air fryer to 400°F (204°C) if your model requires preheating.
Place the asparagus in a large bowl and drizzle with olive oil. Toss until evenly coated.
Sprinkle the garlic powder, black pepper, and grated Parmesan cheese over the asparagus, tossing again to coat.
Arrange the asparagus in a single layer in the air fryer basket or on an air fryer tray lined with perforated parchment paper if desired.
Cook the Air Fryer Asparagus Parmesan for 4–6 minutes, depending on the thickness of the asparagus.
The asparagus is done when it's bright green and the Parmesan is lightly golden.
Let it rest for 2–3 minutes before serving.