Cut potatoes in half lengthwise and then in quarters. Cut each quarter in half and place into a mixing bowl. Drizzle oil on potatoes and add garlic, rosemary, salt and pepper and mix well to evenly coat.
Preheat air fryer for 5 minutes at 400 degrees F.
Add potatoes to the preheated air fryer basket and heat at 400 degrees F for 8 minutes. Once cooking is complete, shake the basket to mix the potatoes. Repeat, heating the potatoes for an additional 8 minutes at 400 degrees F. Let stand 2 minutes before serving.