Prepare the broccoli by cutting them into florets so they are relatively equal in size.
Place the broccoli in a large bowl along with the olive oil, salt and pepper. Toss to combine.
Transfer the broccoli to the air fryer in a single layer. You may need to cook in two batches. Cook until crisp tender, shaking the basket halfway through, for 8-10 minutes total.
Squeeze fresh lemon juice on top and serve immediately.