Rinse the asparagus and pat dry. Snap off the tough ends of the asparagus and discard.
In a mixing bowl, toss the asparagus with olive oil, salt, and pepper until evenly coated.
Arrange the asparagus in a single layer in the air fryer basket. Avoid overcrowding to ensure even cooking.
Cook for 7 minutes, or until the asparagus is tender and lightly browned. If your asparagus spears are particularly thick, they may need an additional 1-2 minutes.
Serve immediately with a squeeze of fresh lemon juice, if desired.