Preheat an air fryer to 320 degrees F (160 degrees C).
Whisk together olive oil, seafood seasoning, and cayenne pepper together in a large bowl. Add peanuts and stir until peanuts are evenly coated. Transfer peanuts to the air fryer basket.
Cook peanuts in the air fryer for 10 minutes. Toss and cook for an additional 10 minutes.
Remove the basket from the air fryer and salt peanuts to taste. Toss peanuts one last time and cook 5 additional minutes. Transfer peanuts to a paper towel lined plate and let cool.