Slice the sweet potatoes into french fry shape, about 1/4-inch thick (if you have a mandolin, you may wish to use that). Submerge cut potatoes in a bowl of cold water and let soak for 20 minutes.
When the fries are almost done soaking, preheat air fryer to 375ºF.
Drain potatoes and pat dry with a paper towel or a lint-free tea/dish towel. Dry bowl and place fries back in bowl. Drizzle with olive oil and sprinkle with salt and pepper
Place a single layer of fries in the basket of the air fryer and cook for 10 minutes, shaking basket once, or until crispy and golden brown. Keep an eye on them towards the end.
Serve immediately, or see notes to keep warm while air frying additional batches.
Video
Notes
Keep fries warm in the oven while you make multiple batches. Spread cooked fries on a wire baking rack placed in a sheet pan in a warm oven (175-200ºF).
Make sweet potato chips, chunks, or wedges. Keep in mind that thinner cuts will cook more quickly, and thicker cuts will take longer.
Prefer no oil? Just omit the olive oil and spray the air fryer rack lightly with cooking spray so the fries don't stick.
Air fryer sweet potato fries can be stored in the fridge, wrapped well, for three to four days. You can also freeze fries for up to one month.
Reheating Suggestions: For best results, reheat sweet potato fries, whether frozen or refrigerated, in your air fryer. Preheat the air fryer to 350°F, and place the fries on the rack in a single layer. Reheat three to six minutes until hot and crispy. The cooking time will vary depending on whether the fries are frozen, and how thick the fries are.