Begin by preheating the air fryer to 400°F for 5 minutes. Meanwhile, wash the potato(es) under cool water. Cut the potato in half lengthwise and lay flat on the cut side. Carefully thinly slice the potato(es) into 1/4″ slices lengthwise. Lay them on their side and thinly slice again on the long edge 1/4″ thick. This will form the fry. It is essential to cut them evenly so they cook evenly.
Pat the fries dry with paper towel to remove extra starch/water. Add to a bowl and toss with the olive oil and seasoning salt. Toss until the desired amount of seasoning is evenly dispersed.
Add the fries to the preheated air fryer basket. Shake lightly into an even layer covering the bottom and cook at 370°F for 15 minutes, tossing the basket once or twice while cooking. You may cook for an additional few minutes depending on your air fryer or desired crispiness.
Serve immediately.