Place chicken thighs in a large bowl and sprinkle with ranch dressing mix.
Toss to coat and then place chicken thighs in a single layer in the air fryer basket.
Lightly spray the top of the chicken thighs with olive oil spray. If you don't have an oil sprayer, you can add 1/2 Tbsp of oil to the bottom of the air fryer basket.
Set air fryer to 380 degrees for 23 minutes.
Half way through cooking time, open the air fryer and flip the thighs.
When cooking time is complete, remove the chicken from the air fryer and serve.